焊接工艺方法对6061_T6铝合金焊接接头疲劳性能的影响

合集下载

焊接缺陷对铝合金焊接接头疲劳性能影响

ｌ４ｓ孵９帅６８Ｉ７０２６１
８４６２８
一
新 ’ 齄
帅．５ｍｍ气孔１个
惋．５ａｍｒ乱１个诈撒小气乳
ｊ辩陷
０茹
容龠～
法对其进行全面研究。在本试验中采用的铝合金制品主要是强化铝合金６０６１板材，其焊接接头方式表现为采用的对接模式。在进行焊接的过程中一还需要在焊接口添加合理的焊丝，这对焊接顷利进行起到非常重要的～％作－用。在本过程中采用的焊丝为５３５６焊丝。根据本次亩￡验中选取的材料进行成分深＾．分析，发现本次试验中两种材料本身化学碗乍常多。具体
・
５８・
科技论坛
焊接缺陷对铝合金焊接接头疲劳性能影响
瞬号
鑫蚰＂妯～、
范清海
童
～
（中车长春轨道客车股份有限公司，吉林长春１３００００）
摘
要：铝合金在人们日常生活中非常常见，采用这种材料制作成的各种产品由于自身性能良好而在社会上得到广泛应用。但是这
１试验材料及试验方法在对铝合金焊接中接头产生的疲劳进行分析中，可以通过试验的方
１０００４０５
１７８．４
耙缺编
３７５７１３
～２６９０ｌ２
蜥＇挪缱
晰ｆ烨琏断于跸缝断于琳鲢断于蚪姥
ｍ域龋
雀埘气拽光酶鹬中０．５ａｍｒ乳３十帅５ａｒｍ气扎２个Ｍ
由于铝合金自身存在非常多的优点，使得这种材料在人．们日常生活中者翻乍常广泛的应用。而目铝合酶蟋焊接的过程中，经常会因为外界因素的影响，造成疲劳断裂的情况出现。这种疲劳凼客ｌ在＾体肉眼艮

转速、焊速对6061-T6 铝合金搅拌摩擦焊性能的影响

6.88
#2
1 200
700
251.608
7.34
#3
1 300
700
232.727
6.64
#4
1 400
700
226.836
6.24
#5
1 500
700
207.242
9.24
#6
1 200
550
247.210
7.56
#7
1 200
600
246.684
7.84
#8
1 200
750
247.504
7.04
焊接速度对焊接接头力学性能和焊缝中“S”线缺陷的影响。研究结果表明，当搅拌头转速保持在 1 200 r ⋅ min-1时，焊接工
艺窗口较宽；当焊接速度为 700 mm ⋅ min-1 、搅拌头的旋转速度为 1 200 r ⋅ min-1时焊缝的强度最高，为 251.608 MPa，焊缝强
度达到了母材的 81.16％。焊接过程中提高搅拌头的旋转速度、减小焊接速度能够减少焊缝中“S”线缺陷的产生。
《铝加工》
2020 年第 2 期总第 253 期
组织性能
转速、焊速对 6061-T6 铝合金搅拌摩擦焊性能的影响
康铭，孙巍，李鹏伟，申智，鄂英凯
（辽宁忠旺集团有限公司，辽阳 111003）
摘要：对 3 mm 厚 6061-T6 铝合金板材的搅拌摩擦焊工艺进行试验研究，分析了在搅拌摩擦焊焊接过程中不同搅拌头转速、
#9
1 200
800
226.903
4.96
2 试验结果及分析
焊速 700 mm· min-1
2.1 拉伸性能在上述工艺参数下得到的 6061-T6 焊缝力学性

焊接工艺对铝合金焊接性能的影响

焊接工艺对铝合金焊接性能的影响发布时间：2021-12-09T10:19:54.263Z 来源：《电力设备》2021年第9期作者：李治[导读] 能实现半自动和全自动焊接，并且焊缝熔深大，强度高，工艺适应性宽等诸多优点，在工业上得到了广泛应用。

（山东电力建设第三工程有限公司山东省青岛市崂山区 266100）摘要：随着社会经济的发展，各地区建设工程逐渐增多，铝合金是建设工程的重要原材料之一，在实际工作期间，铝合金焊接头软化问题给工作人员带来了很大困扰，也是铝合金焊接结构发展的难题，在业内该问题已经引起了热议。

通过实践调查与相关资料分析可以了解到，一般铝合金具有强度高、密度小、耐腐蚀性强、无磁性等特点，目前，在各种焊接结构中，铝合金材料得以广泛利用，并且受到了相关单位与工作人员的青睐。

但是，现阶段铝合金焊接头软化问题较为严重，对于其运用于相关行业发展造成了阻碍性影响，本文将对铝合金焊接头软化问题及改善措施进行具体分析，希望能够提高铝合金在各项工程中的应用质量和效率。

关键词：焊接工艺；铝合金焊接性能；影响引言铝合金以其耐腐蚀性好、密度低、价格优等特点在航空航天、交通运载工具、石油化工等领域得到广泛应用。

随着铝合金应用的广泛发展，铝合金焊接性能越来越重要。

因此，提高铝合金的焊接性能成为铝合金发展的重点。

铝合金焊接材料是铝合金钎焊和熔化焊所必需的填充材料，是决定焊接技术和焊接质量的重要因素之一。

现今，越来越多铝合金焊接采用熔化极惰性气体保护焊（MIG焊），由于其焊接效率高，能实现半自动和全自动焊接，并且焊缝熔深大，强度高，工艺适应性宽等诸多优点，在工业上得到了广泛应用。

1铝合金焊接接头软化因素分析铝合金焊接后，接头软化问题较为常见，在不同焊接工艺及焊接热输入现象下，接头软化程度也不尽相同，但是，热处理强化铝合金焊接接头软化问题极为严重，不利于后续工作的顺利实施。

在退火情况下，非热处理强化铝合金焊接过程中，母材与接头强度方面基本相同，在冷作硬化情况下焊接，母材强度则大于接头强度。

焊接工艺对6061-T6铝合金接头疲劳性能的影响

１０６
１Ｏ
应力循环次数Ⅳ
１０
图２不ｌ司线能量下Ｓ－Ｎ曲线对比
图２中脉动拉伸疲劳试验确定的指定寿命为１×１０的中值疲劳极限分别为：小线能量时为８８ＭＰａ，中线能量时为９２ＭＰａ，大线能量时为
将焊接后的试板按图１的尺寸进行机械加工，得到疲劳试件的疲劳试验是在ＰＬＧ一１００型微机控制高频疲劳试验机上进行的．试验采用的循环应力比Ｒ＝０．１，指定循环寿命取１×１０次．在试验过程中，当疲劳裂纹尺寸足够大导致载荷加不上去时，自动停振，并记录循环次数．试验时各Ｓ—Ｎ曲线测定时均按常规方法进行，即各ｓ—Ｎ曲
０引言
近年来，随着我国轨道车辆的发展，对轨道车辆的用材提出了越来越高的要求．铝合金由于具有密度小、比强度高、易于加工成型、具有良好的耐腐蚀性等诸多优点，被广泛应用于城际列车、地
铝合金，供货状态为，焊接试板尺寸为３００ｍｌＴｌ× ３００ｍｍ×１６Ｉ１１１１３，焊接材料为１．２ｈｉｍ的ＥＲ５３５６焊丝．６０６１一Ｔ６铝合金及ＥＲ５３５６焊丝的化学成分及力学性能如表１和表２所示．
文对不同预热温度和不同层问温度下的１６ｎｑｌＴｌ板厚６０６１一Ｔ６铝合金对接接头的疲劳性能进行了系统的研究，并对其断口形貌进行了分析．

焊接工艺对铝合金焊接性能的影响李学成雷济旭

焊接工艺对铝合金焊接性能的影响李学成雷济旭发布时间：2021-10-13T03:57:14.570Z 来源：《中国科技信息》2021年10月中29期作者：李学成雷济旭[导读] 现如今，我国的经济在快速发展，社会在不断进步，铝合金焊接结构在轨道交通、航空航天、石油化工和船舶等领域广泛应用。

为提高铝合金的焊接性能，本文研究了焊接工艺和焊接材料对焊接性能的影响。

实验材料采用5083-H116铝合金和6082-T6铝合金，利用光学显微镜、显微硬度仪、扫描电镜等测试手段，对接头组织、力学性能进行了分析。

实验结果表明：采用仰焊的焊接接头的硬度较高，焊接质量较好；6082铝合金在拉伸性能上略高于其他材料，且在硬度上较高。

中国航发哈尔滨东安发动机有限公司李学成雷济旭黑龙江哈尔滨 150066摘要：现如今，我国的经济在快速发展，社会在不断进步，铝合金焊接结构在轨道交通、航空航天、石油化工和船舶等领域广泛应用。

为提高铝合金的焊接性能，本文研究了焊接工艺和焊接材料对焊接性能的影响。

实验材料采用5083-H116铝合金和6082-T6铝合金，利用光学显微镜、显微硬度仪、扫描电镜等测试手段，对接头组织、力学性能进行了分析。

实验结果表明：采用仰焊的焊接接头的硬度较高，焊接质量较好；6082铝合金在拉伸性能上略高于其他材料，且在硬度上较高。

关键词：铝合金；焊接工艺；焊接性能；力学性能；显微组织引言铝合金产品是现代工业生产中比较常用的一种合金材料，该材料不仅仅具有较高的热电导率和抗腐蚀能力，还具备较强的物理力学性能，在现代工业中的应用范围越来越广，但是在运用过程中还存在一些问题，尤其是在焊接环节，经常出现裂缝。

之所以出现这个问题，一方面是因为铝合金自身的化学活性比较强，容易形成氧化膜，具有难溶的特点，增加了焊接的难度，另一方面则是因为工作人员在施工过程中焊接方法以及工艺不达标，没有按照正确的施工顺序开展焊接工作。

1激光焊接铝合金的特点（1）功率大的激光头能够稳定焊接质量，随着激光加工的深入开发，功能越来越强大的激光头得到快速的应用。

焊接材料及工艺对铝合金焊接性能的影响

焊接材料及工艺对铝合金焊接性能的影响摘要：近几年来，随着水利工程和智能控制的快速发展，建筑机械产品逐渐走向专业化、多样化，简约化、量化，知识型、知识型。

建筑机械的质量和基本技术依赖于单个系统和大型结构的生产能力，与焊接结构，焊接技术，特别是焊接材料的发展，焊接设备和工艺管理模式密切相关。

关键词：工程机械；结构；工艺技术引言影响焊接产品质量的因素很多，焊接产品的最终产品可能不同于相关标准和使用要求。

焊装制品的经济效益与原设计要求相差较大，焊接技术的应用直接关系到大型金属结构的生产安全和产品的使用寿命。

焊接模具的工艺使用不当，会引起产品焊接模具结构的改变。

对焊接结构质量应采取有效的控制措施，为避免焊接质量问题的发生，本文对此问题的焊接改造控制工艺进行了研究和补充。

一、铝合金焊接材料对焊接性能的影响铝型材焊接材料的物理化学性能直接影响着焊接材料和焊接金属的物理、化学性能，优化焊接材料的性能至关重要。

MIG焊和 TIG焊是目前铝合金最常用的焊接方法。

保护气及焊丝是铝合金的重要焊接材料，铝合金的焊接性能受焊接材料的影响。

1.焊丝的选择选用铝及铝合金焊丝时，不仅要考虑良好的焊接工艺，还应根据接头结构要求，考虑其拉伸强度和塑性(弯曲试验)。

铝合金中镁含量大于3%时，应满足抗冲击性能要求，焊接材料的耐蚀性应达到母材高度或焊缝高度。

因此，选择焊丝时应遵循以下原则：纯铝焊丝的纯度一般不低于母材；铝合金焊丝的化学成分一般或类似母材；铝合金中抗腐蚀元素(镁、锰、硅等)的含量一般不低于母材；不同铝材的焊接温度比对铝不敏感材料的焊接温度高。

必须选用高强度母材的焊丝；不耐腐蚀(经热处理强化的铝合金)的高强度铝合金可以选用不同成分的焊丝，例如抗裂性好的盐酸焊丝。

推荐5,6,7系列母材ER5356焊丝型号为：/AlMg或er5087/almg4.5mnzr7。

两种材料均具有良好的抗裂强度和抗裂孔隙，并具有良好的强度性能。

选用焊丝规格时，首选大直径焊丝。

焊接工艺对铝合金焊接性能的影响

焊接工艺对铝合金焊接性能的影响摘要：镁铝合金在焊接工艺应用时由于金属膨胀系数较大，所以铝合金焊接工艺操作进行时一般很难有效观察清晰其焊接熔池。

因此，一旦焊接间隙过大，很可能促成其焊接熔池下榻；而如果间隙太小又会造成焊接缺陷的出现。

基于此，文章主要提出了铝合金焊接工艺相对普遍的钨极氩弧焊方法，并与之提出了该工艺下焊接对铝合金的主要性能影响，以供参考。

关键词：焊接工艺；焊接性能；铝合金；焊接材料目前仅从理论结合我国的工程实际开展的铝合金焊接的应用及工艺理论研究以及与之比较我国大量开展的各类铝合金产品焊接新技术工艺文献来源及研究方向可知,当前在国内能够采用相对成熟方法的各种先进铝合金材料及其焊接的应用技术工艺中的主要应用领域和主要方法还相对局限较多,原则上这些一般的工艺技术都至少应保证能够完全有效的满足国内与国外的各种先进铝合金产品及其焊接工艺使用需求。

比如从我国工业最初时就被普遍使用的采用乙炔的氧气乙炔焊接法,再进一步引申应用到在我国工业后来开始比较普遍应用的电栓钎焊、点碳焊法等多种电阻钎焊工艺方式,包括搅拌式和摩擦式钎焊、电子钎焊法焊接等多种新型工艺的焊接法。

1.焊接方法的选择考虑到目前国内及当前我国在生产焊接铝合金等多种贵重稀有色金属材料方面所可能要广泛采用涉及到焊接的几种最为普遍采用的焊接技术工艺方法以及所存在着焊接的其中几个较为普遍的焊缝缺陷,比如裂纹、气孔、未熔合等缺陷,所以根据以上原因,主要推荐大家使用的一种焊接技术方法是钨极氩弧焊工艺焊接法。

该等离子电极焊接的等离子工艺技术的主要应用领域范围较为广泛,主要焊接工艺原理上也是通过等离子氩气焊起到隔绝焊接中空气的效果,由于该等离子工艺其焊接电极的本身几乎就不能焊接融入金属于工件基体金属,具有了几乎是不能通过焊接而产生分离出任何其他的有机元素化合物而来焊接的优良技术特性,所以该等离子工艺技术其等离子电弧的有效清除及对被焊接的金属工件表面中残留的有机金属氧化膜效果上亦相对较为之优越与可靠,能够同时可以对一些表面易于发生高温或氧化而破坏的薄铝合金表面直接予以快速成功稳定地进行焊接,具有一种相当成熟良好稳定的焊接成形电弧稳定性,甚至是可实现在极薄较为微小的短路电流条件下焊接电弧仍能稳定的维持在燃烧状态的良好状态,对其他诸如超薄合金板件表面的快速焊接与成形等效果则都已较为成熟理想。

6061-T6铝合金激光焊接接头腐蚀疲劳裂纹扩展

（华中科技大学材料成形及模具技术国家重点实验室，武汉４３００７４）
摘要：目的研究６０６１．Ｔ６铝合金激光焊接接头的腐蚀疲劳裂纹扩展特性，并分析裂纹扩展的影响因素。方
法利用光纤激光器，焊接尺寸为１５０ｍｌＴｌ ×１００ｍｍ×４ｍｍ（焊接方向、横向、熔深方向１的６０６１．Ｔ６铝合金，
Ｗｕｈａｎ４３００７４，Ｃｈｉｎａ）
ＡＢＳＴＲＡＣＴ：Ｔｈｅｐａｐｅｒａｉｍｓｔｏｓｔｕｄｙｃｏｒｒｏｓｉｏｎｆａｔｉｇｕｅｐｒｏｐａｇａｔｉｏｎｃｈａｒａｃｔｅｉｒｓｔｉｃｓｏｆ６０６１一Ｔ６ａｌｕｍｉｎｕｍａｌｌｏｙｗｅｌｄｉｎｇｊｏｉｎｔ
ｕｓｅｄｔｏｗｅｌｄ６０６１－Ｔ６ａｌｕｍｉｎｕｍａｌｌｏｙｂｙｔｈｅｓｉｚｅｏｆ１５０／Ｄ＇Ａｎｘ１００ｍｍｘ４ｍｍ（ｗｅｌｄｉｎｇｄｉｒｅｃｔｉｏｎ，ｔｒａｎｓｖｅｒｓｅａｎｄｐｅｎｅｔｒａｔｉｏｎｄｉ－ｒｅｃｔｉｏｎ）．ＴｈｅｔｈｒｅｅｐｏｉｎｔｂｅｎｄｉｎｇｃｒａｃｋｐｒｏｐａｇａｔｉｏｎｔｅｓｔｏｆＳＥ（Ｂ）ｓａｍｐｌｅａｎｄｔｈｅｍｅｔｈｏｄｏｆｃｏｎｔｉｎｕｏｕｓｄｅｃｒｅａｓｅｏｆＫｗｅｒｅｕｓｅｄ

焊接工艺对铝合金焊接性能的影响

焊接工艺对铝合金焊接性能的影响摘要：近年来，防锈铝由于其优异的性能，已经被广泛地应用于航天、航空、航海、轨道交通、压力容器等多个领域。

5A06铝合金为典型的A1-Mg系防锈铝，具有强度较高、抗腐蚀性稳定和焊接性能良好等优点。

但铝及其合金具有导热性能强、线膨胀系数大、熔点低及高温强度小等特点，使得该类合金的焊接难度较大。

国内相关研究者对铝合金的焊接方法及焊接性能等开展了大量的分析研究。

经调研发现，铝及其合金氩弧焊多采用衬底结构或反面封底焊接的方法，以确保焊缝背面成型良好。

关键词：铝合金；焊接工艺；焊接性能；力学性能；显微组织引言铝合金材料密度小、耐腐蚀、容易加工，且强度比较高，因此，铝合金材料在农业、航空、汽车等领域应用十分广泛。

随着社会的高速发展，铝合金应用越来越广泛，铝合金材料在越来越多的领域中得到推广。

架空输电线路一直使用的是铁塔，铝合金材料与钢材料相比更耐腐蚀，且在相同条件下与Q420钢相比，铝合金可减轻重量66%，而铝合金的成本相比于Q420更低，这促使铝合金塔的研究被推上了研究日程。

在铝合金塔设计过程中，铝合金的选材、材料结构形式和截面型式的确定、焊接方法、焊接工艺和焊丝的选择都显得尤为重要。

1实验材料和方法试验所用焊接材料母材为5083-H116铝合金和6082-T6铝合金（化学成分见表1），厚度8mm，两种合金分别为同一板材下料。

焊丝所用材料为OKAutrod5183和OKAutrod5356（瑞典伊萨ESAB），直径为1.2mm的铝合金焊丝。

焊前对铝合金表面进行抛光处理，以去除表面氧化层。

焊接时分别对两种合金以对接接头形式（如图1）进行横焊和仰焊，焊道顺序如图2所示。

由于铝合金在MIG焊时热输入较TIG焊时大，金属熔化量大，熔敷金属流动性好，且铝合金散热快，易引起熔池塌陷，坡口底部焊缝应在加装表面加出半圆弧槽的加强板。

焊接接头的形式见表2。

2结果与分析2.1接头焊缝成形在TIG电弧加热作用下，由于局部焊接温度高于铝合金母材和焊丝的熔点，焊丝熔化并填充焊缝，在铝母材一侧形成熔焊接头。

60mm厚度6061-T6铝合金板搅拌摩擦焊接接头微观组织与力学性能

60mm厚度6061-T6铝合金板搅拌摩擦焊接接头微观组织与力学性能贺地求;罗维;邬红光【摘要】Double-sided friction stir welding was applied to connection of 6061-T6 aluminum alloy plates, the microstructure and mechanical properties of the joints were investigated. The results show that the microstructure undergoes different changes in the through-thickness direction, the tensile strength of the joint reaches 218MPa, 70% that of the parent material. The re-solution and over-aging of the strengthening phases caused by welding thermal cycle have a great effect on the strength degradation, and the thermal mechanical affected zone of the advancing side is the welding weakness.%采用搅拌摩擦焊接方法对6061-T6铝合金板进行了60mm双面对接焊实验,研究了搅拌摩擦焊接接头的微观组织与力学性能,结果表明:焊缝区微观组织沿厚度方向发生了不同程度的改变,焊接接头强度达到218MPa,为母材强度的70％；焊接热循环引发的金属强化相“重固溶”和“过时效”是接头力学性能下降的重要原因,其中前进侧热机影响区为焊缝薄弱环节.【期刊名称】《材料工程》【年(卷),期】2011(000)009【总页数】5页(P20-24)【关键词】双面搅拌摩擦焊;6061-T6铝合金;微观组织;力学性能【作者】贺地求;罗维;邬红光【作者单位】中南大学现代复杂装备设计与极端制造教育部重点实验室,长沙410083;中南大学现代复杂装备设计与极端制造教育部重点实验室,长沙410083;中南大学现代复杂装备设计与极端制造教育部重点实验室,长沙410083【正文语种】中文【中图分类】TG4536061－T6铝合金属 Al－Mg－Si系可热处理强化铝合金，具有中等强度、良好的塑韧性、耐腐蚀性和挤压性等优点［1］。

焊后热处理对6061-T6铝合金焊接接头组织和力学性能的影响

Trans.Nonferrous Met.Soc.China29(2019)2035−2046Effect of post-weld heat treatment on microstructure and mechanical properties of welded joints of6061-T6aluminum alloyJie YI1,2,Guan WANG2,Shi-kang LI3,Zhi-wen LIU4,Yan-li GONG11.College of Mechanical Engineering,Hunan Industry Polytechnic,Changsha410208,China;2.State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha410082,China;3.Qiuzhen College,Huzhou University,Huzhou313000,China;4.College of Mechanical Engineering,University of South China,Hengyang421001,ChinaReceived1January2019;accepted15August2019Abstract:6061aluminum alloy T-joints were welded by double-pulsed MIG welding process.Then,the post-weld heat treatment was performed on the welded T-joints.The weld microstructure under different aging temperature and time was investigated by transmission electron microscopy and scanning electron microscopy.The mechanical properties were examined by hardness test and tensile test.The results showed that the micro-hardness was sensitive to heat treatment temperature and time.Increasing temperature was beneficial to the shortening of peak aging time.There were a large number of dislocations and few precipitates in the welded joints.With the increase of post-weld heat treatment temperature and time,the density of dislocation decreased.Meanwhile,the strengthening phase precipitated and grew up gradually.When the post-weld heat treatment temperature increased up to200°C, large Q'phases were observed.And they were responsible for the peak value of the micro-hardness in the welded joints.Key words:6061aluminum alloy;double-pulsed MIG welding;post-weld heat treatment;microstructure evolution;mechanical property1IntroductionAluminum alloys have many excellent properties, such as low density,high yield stress to tensile strength ratio and excellent corrosion resistance[1−3].They are widely used in the automotive and railway transportation industry for energy saving and emission reduction. However,the poor weldability of aluminum alloys,such as strong oxidation and thermal conductivity,may lead to many defects of welded joints,for example incomplete fusion,porosity and cracking[4].Pulsed MIG welding is an efficient and high quality welding method for aluminum alloys with good droplet transfer control capability[5].Double pulsed MIG welding is developed based on the pulsed MIG welding.During the welding process,the change of the welding current between the thermal pulse and the thermal matrix leads to the diversification of the weld temperature and stress. Therefore,it may lead to a typical corrugated appearance and strong stirring effect of the weld pool,which has a significant influence on the temperature and stress of the weld pool during the welding process.And it would further affect the quality of the welded joint[6,7].After MIG welding,the strength in some sub-zones (weld zone and heat affected zone)of the welded joint would decrease.Such a strength softening can be restored to a certain extent in subsequent aging treatment.Aging treatment could promote the precipitation in the weld zone and make the structure and chemical composition more uniform[8,9].And then it also could improve the mechanical properties of the welding joint.The post-weld heat treatment process of 6061aluminum alloy was studied by AHMAD and BAKAR[10].It was found that MIG welding can effectively improve the microstructure and mechanicalFoundation item:Projects(2019JJ70077,2019JJ50510)supported by the National Science Foundation of Hunan Province,China;Project(31665004) supported by Open Fund of State Key Laboratory of Advanced Design and Manufacture for Vehicle Body,China;Projects(18B552,18B285)supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaCorresponding author:Shi-kang LI,Tel:+86-158********,E-mail:kangkangli2009@;Jie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−2046 2036properties of the welded joint.RAO et al[11]studied the effect of welding process,heat treatment and filler materials on the cracking tendency in the welding zone of6061aluminum alloy.MUOZ et al[12]found that the hardness of the joint welded by MIG was increased by nearly50MPa of Al−4.5Mg−0.26Sc alloy after the post-weld heat treatment under300°C for1h.CERRI and LEO[13]studied the effect of post-welding-heat treatments on the microstructure and mechanical properties of double lap FSW joints.During exposure at 200and300°C,the tensile strengths and micro-hardness in the nugget center slightly decreased with the increase of time and temperature.GÜRAL et al[14]found that the microstructure of1010steel welded under controlled atmosphere of argon was particularly more homogeneous after intermediate quenching treatment.JEON et al[15] studied the tensile behavior of an as-welded Nimonic 263specimen at room temperature and1053K.With increasing resolutionization time,the YS and UTS tended to decrease along with the increase in tensile ductility.Post-weld heat treatment was usually carried out to improve the strength and hardness of welded joints after welding.In this study,6061aluminum alloy T-joints were welded by double pulsed MIG welding.The effects of single-stage artificial aging heat treatment on mechanical properties and microstructure of the welding joints were systematically studied by means of hardness testing and microstructure observation.The research results will provide guidance for the formulation of heat treatment process for aluminium alloy welded joints.2ExperimentalThe base material under study was a2mm-thick 6061-T6Al alloy sheet and the filler wire adopted was ER5356Al−Mg alloy with a diameter of1.2mm.The chemical compositions of the base metal are given in Table1.Welding operation in this work was fully done by an automatic MIG welder at the self-made fixture. The welding power source used was DP400developed by OTC to provide DP-MIG.Table1Chemical composition of6061-T6alloy(wt.%) Mg Si Fe Cu0.8−1.20.4−0.80.700.15−0.4Cr Mn Zn Ti Al 0.04−0.30.150.250.15Bal.Figure1shows the schematic diagram of the T-joint.The dimensions of the web and the flange were During the welding process,the arc was welded in the X direction on one side.In order to investigate the effect of welding parameters on the mechanical properties of the welded joints,hardness tests were carried out.Hardness measurements on the upper surfaces of polished samples were conducted on a HXD−1000T Vickers hardness testing machine under a load of4.9N and a duration time of10s.In order to study the tensile properties of the alloy under different aging treatments,ambient uniaxial tensile test was carried out on an Instron3369electrical testing machine.Test parameters were also defined according to ASTM:E8-M-04standard;the tensile speed was set as2mm/min.The tensile test sample and dimensions of the tensile test sample are shown in Fig.2.Fig.1Schematic diagram ofT-jointFig.2Tensile test sample(a)and its dimensions(b),and clamping apparatus for tensile tests(c)(unit:mm)The metallographic structure and precipitate morphology of the cross-section of welded joints were observed by means of transmission electron microscopy (TEM)and high resolution TEM(HRTEM).Specimens for TEM were slowly sliced perpendicularly to the seam to about2mm in thickness by wire cut electrical discharge machining from different subzones of the joint, i.e.,the base metal,the weld toe(namely the fusion line), the HAZ zones.All these specimens were first mechanically ground to about100µm in thickness and then further thinned by twin-jet electro-polishing with a solution of25vol.%nitric acid and75vol.%methanol atJie YI,et al/Trans.Nonferrous Met.Soc.China 29(2019)2035−20462037performed on a Tecnai F20TEM system (FEI,Hillsboro,OR,USA)operated at 200kV.3Results and discussion3.1Aging hardening behaviorThe hardness of the welding zone increased with the increase post-weld heat treatment time and temperature,as shown in Fig.3.After reaching the peak value,hardness in the welding zone entered a stable stage.It can be seen that there was a remarkable difference of aging hardening at different aging temperatures.And the time reaching the peak value of the hardness shortened with the increase aging temperature.At the same time,the peak hardness increased until the temperature reached up to 200°C.At the aging temperatures of 160,180and 200°C,the time corresponding the peak hardness was 12,8and 4h,respectively.And the peak hardness values were HV 76,HV 84and HV 82,respectively.The above results showed that the precipitation hardening process in the welding zone depended on the post-weld heat treatment time and temperature.The whole precipitation process was carried out by the diffusion of the solute atoms in aluminum matrix.The diffusion coefficient (D )is a measure of the mobility of the diffusing species,which is related to the temperature,and can be written as 0exp()Q D D RT=-(1)where D 0is the diffusivity constant,Q is the activation energy for diffusion,T is the temperature,R is the gas constant (8.31J/(K·mol)).Fig.3Varation of microhardness of joint at different post-weld heat treatment temperaturesIt can be seen from Eq.(1)that the diffusion coefficient increased exponentially with the increase of temperature.Therefore,the temperature has a great influence on the whole diffusion process.Increasing the diffusion coefficient,leading to accelerating the diffusion process of the solute atoms.Thus,the time for the peak aging was shortened.However,the precipitation hindering the dislocation movement tended to aggregate and coarsen as the temperature increased,resulting in the decrease of the mechanical properties.The peak hardness decreased from HV 84at the temperature of 180°C to HV 82at the temperature of 200°C.The peak aging hardening was not achieved at 140°C for 24h.This was mainly due to the fact that decreasing the aging temperature would greatly reduce the diffusion rate and thus influence the precipitation.Therefore,the time for peak aging would be longer at lower temperature.The highest hardness was HV 84at 180°C,as shown in Fig.3.Thus,the optimum aging process for obtaining the highest mechanical property of 6061aluminum alloy welds was aged at 180°C for 8h.Figure 4shows the hardness of the weldment.It can be seen that the hardness in the welding zone increased with the increase of heat treatment temperature and time.After heat treatment at 180and 200°C,the highest hardness values in the welding zone were HV 84and HV 82,respectively.The hardness in the welding zone was far lower than that in the matrix zone.With the increase of heat treatment time,the hardness in the welding zone increased and reached stable stage after aging for 1h.The supersaturated solid solution state near the welding zone was obtained due to the high thermal cycling temperature.Thus,the hardness near the welding zone increased with the increasing aging time.The peak hardness values at 140,160,180and 200°C were HV 94,HV 95,HV 94and HV 96,respectively.Mg and Si solute precipitates from the supersaturated solid solution and forms fine dispersed phase in the aging process of Al−Mg−Si aluminum alloy [16−18].The two important parameters affecting the precipitation behavior were temperature and time in the same alloy [19].In the aging process,controlling the heat treatment temperature and time could improve the structure,quantity,size and distribution of secondary phase and the mechanical property of the alloy [20−22].Therefore,it is important to establish a reasonable aging process to improve the mechanical property of aluminum alloy.3.2Effect of aging processing on microstructureAccording to the results of the hardness,it can be seen that the weakest zone of the welded joints was located in the heat affected zone.In order to further study the microstructure of the heat affected zone,TEM was used to characterize the microstructure of the welding zone without post heat treatment and the softening zone after post-weld heat treatment at different temperatures.Jie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−2046 2038Fig.4Microhardness of joint at different post-weld heat treatment temperatures:(a)140°C;(b)160°C;(c)180°C;(d)200°CFig.5TEM image(a)and diffraction pattern(b)of joint under[001]Al zone axis in welding zone without heat treatmentdiffraction pattern in the welding zone without post-weld heat treatment.There were a large number of dislocations in the welding zone,and no precipitation was observed,as shown in Fig.5(a).Based on the electron diffraction,as shown in Fig.5(b),there were only diffraction spots of aluminum matrix,which also indicated that there was no precipitation in the welding zone.From the results of TEM,it can be concluded that aluminum matrix at the effect of high temperature welding cycle,leading to a significant decline of the mechanical properties.In addition,there were a large number of dislocations in the matrix.This was because that there was no enough time to make the dislocations completely degenerate during the rapid welding process.Figure6shows the bright field image and the high-resolution of TEM in the softening zone after post-weldJie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−20462039Fig.6Microstructures of softening zone after post-weld heat treatment at140°C for24h:(a,b)TEM images;(c)HRTEM imagenumber of dislocations in the matrix zone,and the amount of dislocations did not decrease compared with that in the matrix without post-weld heat treatment.This was due to the low temperature of140°C,which cannot make the dislocations recover and degenerate.However, it can be clearly seen that there were precipitations after heat treatment at140°C and the length of the precipitation was about100nm,as shown in Fig.6(b). High resolution observations were performed on the precipitation,as shown in Fig.6(c).It was found that the precipitation grew along the[100]direction of the aluminum matrix,and its Fourier transform was inset inFigure7shows the bright field and high resolution images of the softening zone after aging at160°C for 12h.It can be seen that there were still a few dislocations in the matrix zone.But the degradation of the dislocations was more serious than that without heat treatment or aging at140°C for24h.This indicated that there were enough energy at160°C for the recovery and degeneration of th-shaped and needle-shaped phases were observed after aging at160°C for 12h,as shown in Fig.7(b).High resolutions of the phases were performed,as shown in Fig.7(c).Lath-shaped phase grew along the[100]direction of the aluminum matrix.According to Refs.[23−25],the precipitation may be L/Q phase.Theneedle-shaped Fig.7Microstructures of softening zone after post-weld heatJie YI,et al/Trans.Nonferrous Met.Soc.China 29(2019)2035−20462040phases were completely coherent with the aluminum matrix,as shown in Fig.7(c).Figure 8shows the bright field and high resolution images of the softening zone after aging at 180°C for 8h.As shown in Fig.8(a),there were also a few dislocations in the matrix zone and the degradation of the dislocations was more serious.It can be seen that the size of the precipitation was much larger than that in the softening zone after aging at 160°C,as shown in Fig.8(b).High resolutions of the phases were performed,as shown in Fig.8(c).The precipitation grew along the [510]direction of the aluminum matrix.According to Refs.[23−25],the precipitation may be Q′phase.Fig.8Microstructures of softening zone after post-weld heat treatment at 180°C for 8h:(a,b)TEM images;(c)HRTEM Simultaneously,there were much larger number and bigger size of βphases.Figure 9shows the bright field TEM and high resolution images of the softening zone after aging at 200°C for 4h.As can be seen from Fig.9(a),there were a few number of dislocations in the matrix zone.Most of the dislocations have been degenerated during heat treatment,which was similar to the softening zone after heat treatment at 180°C for 8h.The size of precipitation after aging at 200°C for 4h was bigger than that in the softening zone after aging at 180°C for 8h.High resolutions of the phases were performed,as showninFig.9Microstructures of softening zone after post-weld heat treatment at 200°C for 4h:(a,b)TEM images;(c)HRTEMJie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−20462041Fig.9(c),and found that the precipitation grew along the [150]direction of the aluminum matrix.According to Refs.[23−25],the precipitation may be Q′phase.At the same time,the number of the precipitation was larger and the size was bigger.According to above analysis,the microstructure evolution at different temperatures was mainly reflected by two aspects:the precipitation evolution and the dislocation evolution.There were a large number of dislocations in the welded parts.Although the welding zone was affected by the welding thermal cycle during welding process,the dislocations did not change significantly because of the short duration of the welding heat.That is to say,the dislocations containing in the base metal were still stored in the matrix.With the increase of post-weld heat treatment temperature,the number of dislocations decreased.At the post-weld heat treatment temperature of140°C,the number of dislocations did not change significantly.However,the number of dislocations decreased significantly after post-weld heat treatment at160and180°C.After the post-weld heat treatment at160°C,the dislocations almost disappeared.There was no precipitates in the welding zone after welding process.This indicated that the precipitates existing in the base metal could be dissolved back into the matrix due to the influence of welding heat during the welding process.During the post-weld heat treatment at different temperatures,the secondary phase precipitated continuously with the decrease of dislocations and the size of secondary phase increased with the increase of heat temperature.Some lath-like L/Q″phases precipitated after heat treatment at140°C for24h.After heat treatment at160°C for12h,there were not only the L/Q″phases,but also small size,needle-like phases were observed.The needle-like phases were coherent with the matrix.During the heat treatment at180°C for8h,the number of the dislocations decreased and the precipitations grew up,forming the larger Q′phase. Increasing the heat treatment temperature up to200°C, the dislocations completely disappeared and the precipitation was mainly the Q′phase.The size of the precipitation was bigger than that heat treated at180°C for8h.The profiles after heat treatment at200°C for4h exhibited the highest micro-hardness,which was attributed to the precipitation of the Q′phase.3.3Mechanical propertiesBy means of uniaxial tensile tests at ambient temperature,the engineering stress versus displacement curves for the specimens under different heat treatment conditions were obtained,as shown in Fig.10.It can be seen that the welded alloy exhibited poor tensile After heat treatment,the engineering stress of the welded joints improves considerably with limited increase of the elongation.As aging temperature extended,the engineering stress and elongation increased.This result indicates that the aging heat treatment was beneficial to improving engineering stress of the welded joints. However,the engineering stress increased with the aging temperature increasing to200°C,while the elongation declined.The welded joints aged at180°C for8h exhibit high tensile strength and elongation.As we know, keeping large ductility at the high strength can result in a significant increase in toughness[26,27].Therefore,the welded joints aged at180°C for8h can better cover the needs for high damage tolerance and high durabilityindustry.Fig.10Ambient uniaxial tensile stress−displacement curves of welded alloy at different heat treatment temperatures3.4Fracture morphologyFigure11shows the fracture morphologies of tensile specimens of the welded alloy without heat treatment.In the low magnification image presented in Fig.11(a),the fractured cross section exhibits a planar area.The fracture surfaces of the tensile specimens are relatively smooth and have a lot of dimples with different sizes and depths on the upper surface.The average diameter of the dimples was approximately10μm,as shown in Figs.11(c)and(d).These shallow and small dimples correspond to the inferior ductility of the welded joint.While the river pattern fracture surface which indicated the brittle fracture was observed on the bottom surface.According to the fracture surface,it can be seen that the crack may originate from the upper surface of the tensile sample.After a relatively strong plastic deformation,the crack extended to the center of the fracture surface through the dimples,and finally led to the fracture of the tensile sample by brittle fracture.A detailed view of the fracture surface morphology analyzed by scanning electron microscopy is presented in2042Jie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−2046 Fig.11Tensile fracture morphologies of welded sample without aging treatmentJie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−20462043magnification image presented in Fig.12(a),the fracture surfaces of the tensile specimens are unsmooth and shear crack characteristics was observed.Closer inspection inside the fracture surface,there existed uniform rip edges and equiaxed dimples,which indicated that a large plastic deformation was achieved during the process of tensile due to the high energy characteristics of shear crack and rip edge.The average diameter of the dimples was approximately10μm,as shown in Figs.12(c)and (d).Compared with the fracture morphology of the sample without aging,the fracture morphology of the sample aged at140°C for24h was more uniform,which showed that recrystallization might occur in this alloy at this aging treatment.For the sample aged at160°C for12h,the fracture morphology is shown in Fig.13.In the low magnification image presented in Fig.13(a),the fracture surfaces of the tensile specimens are unsmooth and a fairly wide range of dimple sizes covers this surface.The diameters of the shallow dimple ranged from10to 30μm.Closer inspection inside the fracture surface, there was no rip edge,which indicated the low yield strength,as shown in Figs.13(c)and(d).Figure14shows the fracture morphology of the tensile sample aged at180°C for8h.In the low magnification image presented in Fig.14(a),the fracture morphology exhibited a markedly different fracture surface morphology in comparison to the fracture morphologies shown in Figs.11−13.The fracture surface of the tensile specimens at180°C for8h was relatively smooth.The typical intergranular fracture characteristic was observed,as shown in Fig.14(d).This intergranular character was also observed in the fracture morphology of the tensile sample aged at200°C for4h in Fig.15(d). However,a clear distinction in high magnification fracture morphologies can be found,as shown in Figs.14(d)and15(d).There are a number of fine and shallow dimples covering the intergranular fracture surfaces of the tensile sample aged at200°C for4h (Fig.15(d)),while the fracture surface of the tensile specimens aged at180°C for8h is very smooth (Fig.14(d)).This distinction is mainly attributed to the different grain boundary microstructures in two aging conditions.According to the study of WANG et al[27], the precipitate free zone as well as the continuous and coarse grain boundary precipitates weakens the grain boundary and leads to the intergranular fracture with smooth surfaces under the treatment of T6.For the over-aged specimen,micro-voids nucleate primarily at the discontinuous and coarse grain boundary precipitates during tensile test,and then grow and coalesce within the wide precipitate free zone,which form the fine and2044Jie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−2046 Fig.14Tensile fracture morphologies of sample aged at180°C for8hJie YI,et al/Trans.Nonferrous Met.Soc.China29(2019)2035−20462045shallow dimples covering intergranular fracture surface. It can be seen from the above analyses that aging heat treatment has significant influences on the microstructure and mechanical properties of the welded joints.4Conclusions(1)In the aging heat treatment process,the micro-hardness is sensitive to post-weld heat treatment temperature and time.Increasing temperature is beneficial to the shortening of peak aging time.(2)The mechanical properties of the welded joints are greatly improved after heat treatment due to precipitates.The profiles after heat treatment at200°C for4h exhibit the highest micro-hardness,which is attributed to the precipitation of the Q′phase.(3)In the welded joints without heat treatment, there are a lot of dislocations and few precipitations in the welding zones because of the short duration of the welding heat.With the increase of post-weld heat treatment temperature and aging time,the density of the dislocation in the heat affected zone decreases. References[1]LIU L,WU Y X,GONG H,WANG K.Modification of constitutivemodel and evolution of activation energy on2219aluminum alloy during warm deformation process[J].Transactions of Nonferrous Metals Society of China,2019,29(3):448−459.[2]LIU Z W,LI L X,LI S K,YI J,WANG G.Entrance shape design ofspread extrusion die for large-scale aluminum panel[J].The International Journal of Advanced Manufacturing Technology,2019, 101(5−8):1725−1740.[3]LIU Z W,LI L X,LI S K,YI J,WANG G.Simulation analysis ofporthole die extrusion process and die structure modifications for an aluminum profile with high length–width ratio and small cavity [J].Materials,2018,11(9):1517−1536.[4]YI J,ZHANG J M,CAO S F,GUO P C.Effect of welding sequenceon residual stress and deformation of6061-T6aluminium alloy automobile component[J].Transactions of Nonferrous Metals Society of China,2019,29(2):287−295.[5]WU K Y,YIN T,DING N,ZENG M,LIANG Z Y.Effect of phaseon the behavior of metal transfer in double-wire pulsed GMAW[J].The International Journal of Advanced Manufacturing Technology, 2018,97(9−12):3777−3789.[6]MESEGUER-VALDENEBRO J L,PORTOLES A,MATÍNEZ-CONESA E.Electrical parameters optimisation on welding geometry in the6063-T alloy using the Taguchi methods[J].The International Journal of Advanced Manufacturing Technology,2018,98(9−12): 2449−2460.[7]ZHAN X H,WU Y F,KANG Y,LIU X,CHEN X D.Simulated andexperimental studies of laser-MIG hybrid welding for plate-pipe dissimilar steel[J].The International Journal of Advanced Manufacturing Technology,2019,101(5−8):1611−1622.[8]SAFARBALI B,SHAMANIAN M,ESLAMI A.Effect of post-weldheat treatment on joint properties of dissimilar friction stir welded 2024-T4and7075-T6aluminum alloys[J].Transactions ofNonferrous Metals Society of China,2018,28(7):1287−1297. [9]OZER G,KARAASLAN A.Properties of AA7075aluminum alloyin aging and retrogression and reaging process[J].Transactions of Nonferrous Metals Society of China,2017,27(11):2357−2362. [10]AHMAD R,BAKAR M A.Effect of a post-weld heat treatment onthe mechanical and microstructure properties of AA6061joints welded by the gas metal arc welding cold metal transfer method[J].Materials and Design,2011,32(10):5120−5126.[11]RAO K P,RAMANAIAH N,VISWANATHAN N.Partially meltedzone cracking in AA6061welds[J].Materials and Design,2008, 29(1):179−186.[12]MUNOZ A C,RUCKERTET G,HUNEAU B,SAUVAGE X,MARYA parison of TIG welded and friction stir welded Al−4.5Mg−0.26Sc alloy[J].Journal of Materials Processing Technology,2008,197(1):337−343.[13]CERRI E,LEO P.Mechanical properties evolution during post-welding-heat treatments of double-lap Friction stir welded joints[J].Materials and Design,2011,32(6):3465−3475.[14]GÜRAL A,BOSTAN B,OOZDEMIR A T.Heat treatment in twophase region and its effect on microstructure and mechanical strength after welding of a low carbon steel[J].Materials and Design,2007, 28(3):897−903.[15]JEON M,LEE J H,WOO T K,KIM S.Effect of welding andpost-weld heat treatment on tensile properties of Nimonic263at room and elevated temperatures[J].Metallurgical and Materials Transactions A,2011,42(4):974−985.[16]LIU C H,LAI Y X,CHEN J H,TAO G H,LIU L M,MA P P,WUC L.Natural-aging-induced reversal of the precipitation pathways inan Al−Mg−Si alloy[J].Scripta Materialia,2016,115:150−154. [17]POGATSCHER S,ANTREKOWITSCH H,LEITNER H,EBNER T,UGGOWITZER G G.Mechanisms controlling the artificial aging of Al−Mg−Si alloys[J].Acta Materialia,2011,59(9):3352−3363. [18]MARIOARA C D,ANDERSEN S J,JANSEN J,ZANDBERGEN HW.The influence of temperature and storage time at RT on nucleation of theβ″phase in a6082Al−Mg−Si alloy[J].Acta Materialia,2003,51(3):789−796.[19]KUMAR N,JAYAGANTHAN R,BROKMEIER H G.Effect ofdeformation temperature on precipitation,microstructural evolution, mechanical and corrosion behavior of6082Al alloy[J].Transactions of Nonferrous Metals Society of China,2017,27(3):475−492. [20]WANG F F,MENG W,ZHANG H W,HAN Z Q.Effects ofunder-aging treatment on microstructure and mechanical properties of squeeze-cast Al−Zn−Mg−Cu alloy[J].Transactions of Nonferrous Metals Society of China,2018,28(10):1920−1927.[21]KHALFALLAH A,RAHO A A,AMZERT S,DJEMLI A.Precipitation kinetics of GP zones,metastableη′phase and equilibriumηphase in Al−5.46wt.%Zn−1.67wt.%Mg alloy[J].Transactions of Nonferrous Metals Society of China,2019,29(2): 233−241.[22]LI J F,HUANG J,LIU D Y,CHEN Y,ZHANG X,MA P.Distribution and evolution of aging precipitates in Al−Cu−Li alloy with high Li concentration[J].Transactions of Nonferrous Metals Society of China,2019,29(1):15−24.[23]YANG W,JI S,HUANG L,SHENG X,LI Z,WANG M.Initialprecipitation and hardening mechanism during non-isothermal aging in an Al−Mg−Si−Cu6005A alloy[J].Materials Characterization, 2014,94:170−177.[24]EDWARDS G A,STILLER G A,DUNLOP G L,COUPER M J.The precipitation sequence in Al−Mg−Si alloys[J].Acta Materialia,。

设备焊接工艺参数优化对焊接接头疲劳性能的影响研究

设备焊接工艺参数优化对焊接接头疲劳性能的影响研究焊接是制造业中常见的连接工艺之一，而焊接接头的质量直接关系到产品的性能和可靠性。

在焊接过程中，设备的焊接工艺参数对焊接接头的疲劳性能有着重要的影响。

本文将探讨设备焊接工艺参数优化对焊接接头疲劳性能的影响，并分析其原理和影响因素。

焊接接头的疲劳性能是指在受到周期性加载下，焊接接头不会出现疲劳破坏的能力。

而焊接接头的疲劳性能受到多种因素的影响，其中包括焊接材料的选择、焊接工艺参数的设定以及焊接接头的几何形状等。

而设备焊接工艺参数优化作为焊接质量控制的关键环节之一，直接影响着焊接接头的疲劳性能。

首先，设备焊接工艺参数的优化应考虑到焊接材料的性质。

不同材料在焊接过程中具有不同的熔化温度、热导率和机械性能等特性，因此需要根据材料的性质来确定合适的焊接工艺参数。

例如，对于高强度钢材料，可以采用高功率、高速度的焊接工艺，以确保焊接接头的强度和耐久性。

其次，设备焊接工艺参数的优化还应考虑到焊接接头的几何形状。

焊接接头的形状对于焊接质量和疲劳性能具有重要影响。

一般来说，焊接接头的几何形状应设计成尽量均匀、光滑的形式，避免出现尖角和突变等缺陷，从而提高焊接接头的疲劳寿命。

此外，设备焊接工艺参数的优化还应考虑到焊接过程中的热影响区域。

焊接过程中会产生大量的热量，而热量的积累会导致焊接接头的热影响区域扩大，从而影响焊接接头的力学性能和疲劳性能。

因此，在设定焊接工艺参数时，需要控制好焊接过程中的温度和焊接速度，以减小热影响区域的大小，提高焊接接头的疲劳寿命。

综上所述，设备焊接工艺参数的优化对焊接接头的疲劳性能有着重要的影响。

在实际生产中，需要根据焊接材料的性质、焊接接头的几何形状以及焊接过程中的热影响区域等因素，合理设定焊接工艺参数，以确保焊接接头具有良好的疲劳性能和稳定的焊接质量。

焊接材料及工艺对铝合金焊接性能的影响

焊接材料及工艺对铝合金焊接性能的影响目前结合实际焊接工艺与大量的焊接工艺文献来源可知，当前采用的铝合金焊接工艺应用方法较多，原则上一般都能够满足其铝合金焊接需求。

比如最初普遍采用的氧气炔焊接法，再到后来比较常用的电栓焊、点焊等电阻焊方式，包括搅拌摩擦焊、电子焊等工艺焊接法。

不过，显然这些焊接工艺应用时存在一些潜在性缺憾。

例如采用氧气炔焊接时，如果不能良好控制气焊火焰的集中温度，则会造成裂纹缺陷出现；而电焊、搅拌焊等方式又对其焊接接头的作业要求较高，所以存在工艺应用的场地限制和约束。

基于此，研究焊接材料与焊接工艺的对其焊接性能的主要影响，应能选用合理的焊接方法，同时要了解焊接接头裂缝的形成机理等有关内容，以此才能选择适宜的焊接材料与操作工艺，保障铝合金焊接质量。

1.焊接方法的选择考虑到当前焊接铝合金等有色金属所采用的普遍焊接工艺方法存在的普遍缺陷，比如裂纹缺陷、场地限制等，所以文章主要推荐的是钨极氩弧焊工艺焊接法。

该焊接工艺应用较为广泛，主要原理是通过氩气隔绝空气效果，由于其本身不融于金属，具有不能产生其他化合物的特性，所以其电弧清除焊接工件的氧化膜效果较为可靠，能够对易于氧化的铝合金予以成功焊接，具有良好的电弧稳定性，甚至在较为微小的电流下仍能维持燃烧状态，对诸如超薄合金板的焊接效果较为理想。

因此，选用该焊接工艺时，可以着重考虑焊接工件的厚度及接头调整参数等。

由于铝合金本身的化学活泼性表现明显，所以其金属材料发生化学反应的可能性较高，在焊接时特别容易和空气中的水分加以产生氧气反应。

因此，考虑到采用钨极氩弧焊的作业焊枪其保护范畴较小，可能影响到焊缝金属保护效果，处于热影响区受热作用下易与空气发生气体反应，在焊接时产生气孔或其他氧化物等缺陷。

基于此，一般采用该焊接工艺会在焊接工件上设置必要的保护气罩，使其自气罩出来的气体能够回流到焊件周围形成一个立体空间的氩气保护氛围，故此能够降低空气对其焊接工艺表现出的气孔或氧化物等缺陷影响。

焊接工艺优化对铝合金材料力学性能的影响

焊接工艺优化对铝合金材料力学性能的影响随着科技的不断进步，铝合金材料的应用也越来越广泛。

铝合金材料在航空、汽车、电子等领域中得到了广泛的应用，而焊接是连接铝合金材料的重要工艺之一。

焊接工艺的优化可以显著影响铝合金材料的力学性能，因此在铝合金材料的焊接加工工艺中，优化焊接工艺至关重要。

一、铝合金材料的力学性能铝合金材料因其具有优异的强度、韧性、耐腐蚀性和轻质等特点被广泛应用。

常用的铝合金主要包括2***、5***、6***、7***等系列，其中以6***系列的铝合金应用最为广泛。

这主要是因为6***系列的铝合金具有良好的加工性能和强度，同时具有一定的耐腐蚀性能。

铝合金材料的力学性能一般指其强度和韧性等指标。

强度指的是材料在受力作用下的抵抗能力，通常包括屈服强度、抗拉强度和硬度等指标。

韧性指的是材料在受力作用下的能量吸收能力，通常包括延伸率和冲击韧性等指标。

铝合金材料的力学性能是由其原材料冶炼、热处理、机械加工等环节的加工工艺和焊接工艺等因素共同决定的。

二、影响铝合金材料力学性能的因素1. 热处理工艺铝合金经过冷变形后，会形成母体和弥散相的组织结构。

热处理工艺能够改变组织结构，通常包括时效处理、淬火和回火处理等。

适宜的热处理工艺能够改善材料的力学性能，如提高强度和韧性等。

2. 机械加工工艺铝合金材料在进行机械加工的过程中，会产生应力、氧化皮和裂纹等缺陷。

适宜的机械加工工艺能够减小这些缺陷，提高材料的力学性能。

3. 焊接工艺焊接是连接铝合金材料的重要工艺之一，是铝合金产品的核心。

焊接工艺能够改变材料的组织结构和力学性能，进而影响其可靠性和使用寿命。

三、焊接工艺优化对铝合金材料力学性能的影响铝合金焊接工艺的优化需要综合考虑多个方面的因素：1. 焊接参数优化焊接参数直接影响焊缝的质量，包括焊接电流、焊接电压、焊接速度、焊接角度等。

适宜的焊接参数能够保证焊缝的质量和强度，进而保证铝合金材料的力学性能。

2. 焊接材料优化不同的焊接材料具有不同的化学成分和力学性能。

焊接参数和焊接顺序对al6061-t6铝合金t形接头残余应力和变形的影响

Received 1 April 2019; accepted 19 August 2019
Abstract: The distribution of temperature and then the distribution of residual stress and distortion in the stiffened aluminum alloy Al6061-T6 plates under the metal inert gas (MIG) welding process were investigated by three dimensional thermo-mechanical coupled finite element model using Ansys software. The properties of materials were considered temperature-dependent and the filler metal was added to the workpiece by the element birth and death technique. In three modes of current, two differபைடு நூலகம்nt speeds and two various sequences, the distribution of residual stress and distortion were calculated and analyzed. The results showed that increase in welding speed decreased the vertical deflection in the plate, transverse shrinkage and angular distortion of plate and the lateral deflection of stiffener, but increased the maximum longitudinal tensile stress in the plate and stiffener. Furthermore, increase in current increased the residual stress and deformation in the plate and stiffener, and the change in the welding sequence changed the distribution of the distortion in the plate and the stiffener without significant change in the distribution of the longitudinal residual stress. Key words: welding parameters; welding sequence; residual stress; distortion

6061-T6中厚板铝合金激光焊接工艺研究

6061-T6中厚板铝合金激光焊接工艺研究针对6mm厚6061-T6铝合金试板做了大功率激光焊接试验，从焊接稳定性入手，分别讨论了离焦量、焊接速度、保护气体流量以及激光功率对激光焊接的影响，确定了中厚板铝合金在大功率激光焊接条件下的最佳激光焊接工艺参数。

最后，利用Simufact Welding软件针对试验结果进行了模拟验证。

结果表明：在采用氩气作为保护气体的条件下，最佳气流量范围为20L/min～25L/min。

在离焦量为-6mm～-4mm时，焊缝的熔深与焊接的稳定性均达到一个较好水平。

中厚板铝合金激光焊接难以得到临界焊透焊缝，往往表现为“透则漏”，因此容易得到部分焊透焊缝，此时小孔的稳定性最差，而全熔透焊的稳定性相对较好。

關键词：激光焊接;焊接角度;数值模拟;气孔率;力学性能6061-T6铝合金具有优良的焊接特性、良好的抗腐蚀性、韧性高且加工性能优异、氧化效果极佳等优良特点，逐渐替代了传统的钢材，广泛应用于电子、精密仪器、通讯以及航天领域[1-3]。

激光焊接是一种先进的连接技术，具有热输入小，变形小等优势。

但是由于深熔焊焊接过程铝合金材料对激光反射率高，激光能量吸收率很低、合金元素烧损严重，焊接过程不稳定，以及铝合金本身特殊的物理性质使得这种工艺还不成熟，焊接时存在着易产生焊缝下塌和气孔缺陷等问题[4-7]。

本文采用6mm厚的6061-T6中厚铝板铝合金材料，进行单因素激光焊接试验，研究不同的焊接工艺参数对激光焊接焊缝成形和焊缝质量的影响，优化中厚板铝合金激光焊接工艺参数，总结工艺参数与焊接接头形状的关系，并对接头的金相组织与力学性能进行观察与测试得出接头形状与金相组织及力学性能的相关性。

1 试验材料及方法试验材料为板厚6mm的6061-T6铝合金，化学成分如表1，实验板的尺寸为。

试验采取氩气为保护气体，通过控制单因素变量进行试验。

激光器是YLR-6000光纤激光器，激光焊接实验中保护气嘴与试验板表面法线的夹角为，距离实验板表面为5mm，焊接前用带有丙酮的棉布将实验板的表面擦拭干净，防止污染实验板，影响试验结果，焊接过程中保持激光垂直照射在焊板上。

焊接材料及工艺对铝合金焊接性能的影响分析

焊接材料及工艺对铝合金焊接性能的影响分析摘要：随着我国经济发展水平的进一步提升，铝合金焊接结构的应用范围不断扩大，应用程度不断加深，在交通、航天和船舶等领域应用较广，对铝合金焊接性能的提升提出了新的要求和挑战，其中，焊接材料以及焊接工艺是焊接性能的重要影响因素，要对其进行分析。

基于此，本文介绍了铝合金焊接材料对焊接性能的影响，会影响焊接接头的力学性能和裂纹敏感性，然后从不同的气焊接头、不同的焊接溶剂和不同的焊接火焰三方面入手分析了铝合金焊接工艺对焊接性能的影响，对铝合金焊接性能的提升提供一些借鉴和参考。

关键词：焊接材料；焊接工艺；铝合金焊接性能引言：铝合金有着较强的耐腐蚀性，较低的密度和优惠的价格，被广泛应用于交通工具、航天航空以及石油化工等领域。

随着铝合金应用范围的进一步扩大，焊接铝合金性能越来越受到重视和关注。

所以，要把提升铝合金焊接性能作为发展铝合金的重要内容。

可以从铝合金焊接材料和焊接工艺的选择两个角度出发，综合分析和考虑各项影响因素，选取提升性能的最优方案。

1.铝合金焊接材料对焊接性能的影响焊丝是常见的焊接材料，也包括很多类型，根据产品的不同特性可以选择不同类型的焊丝，通常情况下，按照母材的应用性能以及成分进行选取，可以大致选择不同质和同质两种类型的焊丝。

同时，也可以依据构架组成空间暗淡或者是其他要求选择焊接工艺类型，比如，焊缝的抗腐蚀性、抗裂性和大小。

在一般的焊接中，主要以母件的成分和材料为选择依据，需要选取和母件规格型号相一致的焊丝开展焊接工作，来有效提升不同构件部分的焊接性能，在进行焊接时要考虑以下方面的内容。

1.1影响焊接接头的力学性能焊丝有着不同的规格型号，不同型号间焊丝自身的强度也有所不同。

针对在完成焊接后对抗裂性等力学性能要求较高的铝合金构件，可以选择具有高强度的焊丝，把焊丝强度控制在4000系之上，相反情况下，在完成焊接后，还要结合变化情况进行再次加工的铝合金构件，就要选择具有低强度的焊丝，焊丝最好包含硅成分，来确保在结束焊接开展再加工工艺时焊丝不会出现断裂的情况。

焊后热处理对6061-T6接头组织和性能的影响研究

焊后热处理对6061-T6接头组织和性能的影响研究韦宝权;袁红昆;祝影;魏鹏尧;金文福【摘要】以6061-T6铝合金MIG焊接试样为基体,焊后分别进行175℃×8h、525℃×30min+175℃×8h两种热处理,分析焊后不同热处理制度对焊缝组织及性能的影响.研究结果表明,经时效处理的接头组织不均匀性和强化相的分布得到改善,抗拉强度提高36.39MPa.经固溶+时效处理的接头,热影响区的Mg2Si回溶,热影响区消失,抗拉强度提高58.42MPa.【期刊名称】《铝加工》【年(卷),期】2017(000)006【总页数】5页(P54-58)【关键词】6061-T4铝合金;焊接;热处理;显微组织;力学性能【作者】韦宝权;袁红昆;祝影;魏鹏尧;金文福【作者单位】辽宁忠旺集团有限公司,辽阳111000;辽宁忠旺集团有限公司,辽阳111000;辽宁忠旺集团有限公司,辽阳111000;辽宁忠旺集团有限公司,辽阳111000;辽宁忠旺集团有限公司,辽阳111000【正文语种】中文【中图分类】TG441.8;TG457.146系铝合金经固溶人工时效（T6）后具有良好的力学性能、抗腐蚀性能及工艺性能，因此成为车体轻量化的理想材料[1～3]。

铝合金车体制造多以MIG和TIG弧焊为主，焊后接头软化严重，直接影响车辆安全和使用寿命[4]。

目前，提高铝合金焊接接头性能的研究主要集中在焊接工艺、焊接方法以及填充材料方面，并取得了丰硕的研究成果，但关于焊后热处理的研究甚少[5～6]。

本文以热处理强化型6061铝合金为对象，研究焊后热处理对焊接接头组织和性能的影响，为扩大铝合金的工程化应用积累基础数据。

母材选用6061-T6铝合金，尺寸为300mm×150mm×4mm。

母材的化学成分及力学性能如表1、表2所示。

焊前使用气动钢丝刷对母材表面进行打磨，使其露出金属光泽，采用福尼斯TPS 5000焊机对材料进行MIG焊接。

焊接工艺对耐候钢焊接接头疲劳性能的影响

焊接工艺对耐候钢焊接接头疲劳性能的影响发布时间：2021-09-16T06:07:48.712Z 来源：《建筑实践》2021年5月第13期作者：范磊[导读] 焊接是当前连接不同金属材料之间经常使用的一种方式，焊接本身有着非常强的实用性，在实际使用的时候能够发挥非常大的作用，但是在长时间的焊接之后，焊接头必然会产生疲劳，范磊武汉华康世纪医疗股份有限公司湖北武汉 430000摘要：焊接是当前连接不同金属材料之间经常使用的一种方式，焊接本身有着非常强的实用性，在实际使用的时候能够发挥非常大的作用，但是在长时间的焊接之后，焊接头必然会产生疲劳，从而对焊接工作造成一定的影响，因此在当前的使用中，需要对这些影响有一定的了解，本文主要对耐候钢焊接中对焊接头疲劳性能的影响进行分析，希望对相关的从业人有一定的参考作用。

关键词：焊接工艺，耐候钢；焊接接头引言：焊接接头的可靠性对钢结构的使用安全至关重要。

焊接接头的可靠性研究包括钢板的冷裂纹敏感性、钢板芯偏析层对焊接加工的影响、供料状态对焊接接头力学性能的影响等。

耐疲劳性研究是焊接接头力学性能研究中非常重要的一部分。

一般来说，焊接接头的焊接环境和焊接方法对焊接接头的显微组织和性能有显着影响，进而影响焊接接头的疲劳性能。

为了能够充分掌握焊接工艺对耐候钢焊接头疲劳性能的影响，本文主要使用了400Mpa极限耐候钢，这样才可以对焊接制备工艺的抗疲劳性有一个充分的了解。

一、本次实验中的四种焊接技术在本次的实验中，主要使用了四种焊接工艺，其中分别为30kj/cm埋弧焊1，30kj/cm埋弧焊2，20kj/cm气保焊以及20kj/cm气保大间隙焊接。

（一）埋弧焊埋弧焊（包括埋弧堆焊和电渣堆焊）是一种电弧在焊剂层下燃烧的焊接方法。

其焊接质量稳定、焊接生产率高、无电弧、烟尘少等固有优点使其成为制造压力容器、管段、箱形梁柱等重要钢结构的主要焊接方法。

近年来，虽然出现了许多高效率、高质量的新型焊接方法，但埋弧焊的应用领域仍未受到影响。

焊接缺陷对铝合金焊接接头疲劳性能的影响分析

焊接缺陷对铝合金焊接接头疲劳性能的影响分析发布时间：2022-10-18T07:55:33.427Z 来源：《科学与技术》2022年第11期6月作者：岳永健李肇亮[导读] 铝合金这类材料在生活当中十分常见，因材料特性使得制造出的产品性能优越，因此得到广泛应用。

岳永健李肇亮中车青岛四方机车车辆股份有限公司山东青岛266000摘要：铝合金这类材料在生活当中十分常见，因材料特性使得制造出的产品性能优越，因此得到广泛应用。

然而，材料制作成产品过程当中，通常需要利用焊接工艺，焊接过程产生的缺陷对于接头的疲劳性可产生重要影响。

下文简要论述影响焊接接头的因素，结合试验材料，重点对于焊接缺陷这一影响因素进行分析，以供参考。

关键词：铝合金；焊接缺陷；焊接接头；疲劳性能引言：铝合金材料由于本身理化性质、力学特性和工艺特征良好，适用于各行业产品制作当中，焊接结构被应用于航空航天、船舶制造、汽车生产等领域当中。

由于焊接接头在实际使用阶段会承受交变荷载影响，所以其疲劳性能也会发生变化。

部分疲劳缺陷肉眼观察困难，可能影响材料使用安全。

为了预防铝合金材料使用过程出现断裂损坏，需要重点对于其疲劳性能全面分析，寻找原因，制定解决措施，延长材料的使用寿命，保证使用过程安全。

一、影响铝合金焊接接头的疲劳性能因素分析焊接缺陷包括裂纹、气孔、未焊透的情形，是影响铝合金抗疲劳性能的关键，气孔缺陷较为常见，金属凝固的时候，内部气体没有及时溢出，产生气孔，分布在焊缝的周围。

研究人员对于6061铝合金的接头采取抗疲劳试验，结果显示，气孔存在对于接头的抗疲劳性产生的影响主要和气孔宏观尺寸相关，当气孔直径不足0.5mm的时候，对于接头疲劳性影响并不显著。

如果气孔超过0.8mm，疲劳性和余高保留情况相似，当气孔长度在1.2~1.8mm的时候，应力相对集中，在气孔处就会出现断裂[1]。

焊缝余高普遍存在，受到其影响接头焊趾位置受到轴向应力影响，应力集中程度显著提高，所以，需要对余高预留情况合理控制，以提升铝合金焊接位置抗疲劳性能。