焊缝焊射线探伤常见缺陷形状(附底片)

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焊缝RT底片评判规律及典型缺陷图谱

焊缝RT底片评判规律及典型缺陷图谱

焊缝射线照相底片的评判规律一、探伤人员要评片,四项指标放在先*,底片标记齐又正,铅字压缝为废片。

二、评片开始第一件,先找四条熔合线,小口径管照椭圆,根部都在圈里面。

三、气孔形象最明显,中心浓黑边缘浅,夹渣属于非金属,杂乱无章有棱边。

四、咬边成线亦成点,似断似续常相见,这个缺陷最好定,位置就在熔合线。

五、未焊透是大缺陷,典型图象成直线,间隙太小钝边厚,投影部位靠中间。

六、凹只在仰焊面,间隙太大是关键,凹未透要分清,凹透度成弧线。

七、未熔合它斜又扁,常规透照难发现,它的位置有规律,都在坡口与层间。

八、横裂纵裂都危险,横裂多数在表面,纵裂分布围广,中间稍宽两端尖。

九、还有一种冷裂纹,热影响区常发现,冷裂具有延迟性,焊完两天再拍片。

十、有了裂纹很危险,斩草除根保安全,裂纹不论长和短,全部都是Ⅳ级片。

十一、未熔和也很危险,黑度有深亦有浅,一旦判定就是它,亦是全部Ⅳ级片。

十二、危害缺陷未焊透,Ⅱ级焊缝不能有,管线根据深和长,容器跟着条渣走**。

十三、夹渣评定莫着忙,分清圆形和条状,长宽相比3为界,大于3倍是条状。

十四、气孔危害并不大,标准对它很宽大,长径折点套厚度,中间厚度插入法。

十五、多种缺陷大会合,分门别类先评级,2类相加减去Ⅰ,3类相加减Ⅱ级。

十六、评片要想快又准,下拜焊工当先生,要问诀窍有哪些,焊接工艺和投影。

注:*四项指标系底片的黑度、灵敏度、清晰度、灰雾度必须符合标准的要求。

**指单面焊的管线焊缝和双面焊的容器焊缝未焊透的判定标准。

Radiograph Interpretation - WeldsIn addition to producing high quality radiographs, the radiographer must also be skilled in radiographic interpretation. Interpretation of radiographs takes place in three basic steps which are (1) detection, (2) interpretation, and (3) evaluation. All of these steps make use of the radiographer's visual acuity. Visual acuity is the ability to resolve a spatial pattern in an image. The ability of an individual to detect discontinuities in radiography is also affected by the lighting condition in the place of viewing, and the experience level for recognizing various features in the image. The following material was developed to help students develop an understanding of the types of defects found in weldments and how they appear in a radiograph.DiscontinuitiesDiscontinuities are interruptions in the typical structure of a material. These interruptions may occur in the base metal, weld material or "heat affected" zones. Discontinuities, which do not meet the requirements of the codes or specification used to invoke and control an inspection, are referred to as defects.General Welding DiscontinuitiesThe following discontinuities are typical of all types of welding.Cold lap is a condition where the weld filler metal does not properly fuse with the base metal or the previous weld pass material (interpass cold lap). The arc does not melt the base metal sufficiently and causes the slightly molten puddle to flow into base material without bonding.Porosity气孔is the result of gas entrapment in the solidifying metal. Porosity can take many shapes on a radiograph but often appears as dark round or irregular spots or specks appearing singularly, in clusters or rows. Sometimes porosity is elongated and may have the appearance of having a tail This is the result of gas attempting to escape while the metal is still in a liquid state and is called wormhole porosity. All porosity is a void in the material it will have a radiographic density more than the surrounding area..Cluster porosity链状气孔is caused when flux coated electrodes are contaminated with moisture. The moisture turns into gases when heated and becomes trapped inthe weld during the welding process. Cluster porosity appear just like regular porosity in the radiograph but the indications will be grouped close together.Slag inclusions夹渣are nonmetallic solid material entrapped in weld metal or between weld and base metal. In a radiograph, dark, jagged asymmetrical shapes within the weld or along the weld joint areas are indicative of slag inclusions.Incomplete penetration (IP) or lack of penetration (LOP)未焊透occurs when the weld metal fails to penetrate the joint. It is one of the most objectionable weld discontinuities. Lack of penetration allows a natural stress riser from which a crackmay propagate. The appearance on a radiograph is a dark area with well-defined, straight edges that follows the land or root face down the center of the weldment.Incomplete fusion未熔合is a condition where the weld filler metal does not properly fuse with the base metal. Appearance on radiograph: usually appears as a dark line or lines oriented in the direction of the weld seam along the weld preparation or joining area.Internal concavity or suck back凹或吸入is condition where the weld metal has contracted as it cools and has been drawn up into the root of the weld. On aradiograph it looks similar to lack of penetration but the line has irregular edges and it is often quite wide in the center of the weld image.Internal or root undercut部或根部咬边is an erosion of the base metal next to the root of the weld. In the radiographic image it appears as a dark irregular line offset from the centerline of the weldment. Undercutting is not as straight edged as LOP because it does not follow a ground edge.External or crown undercut外部或顶部咬边is an erosion of the base metal next to the crown of the weld. In the radiograph, it appears as a dark irregular line along the outside edge of the weld area.Offset or mismatch错边are terms associated with a condition where two pieces being welded together are not properly aligned. The radiographic image is a noticeable difference in density between the two pieces. The difference in density is caused by the difference in material thickness. The dark, straight line is caused by failure of the weld metal to fuse with the land area.Inadequate weld reinforcement未填满is an area of a weld where the thickness of weld metal deposited is less than the thickness of the base material. It is very easy to determine by radiograph if the weld has inadequate reinforcement, because the image density in the area of suspected inadequacy will be more (darker) than the image density of the surrounding base material.Excess weld reinforcement增强余高is an area of a weld, which has weld metal added in excess of that specified by engineering drawings and codes. The appearance on a radiograph is a localized, lighter area in the weld. A visual inspection will easily determine if the weld reinforcement is in excess of that specified by the individual code involved in the inspection.Cracking裂纹can be detected in a radiograph only the crack is propagating in a direction that produced a change in thickness that is parallel to the x-ray beam. Cracks will appearas jagged and often very faint irregular lines. Cracks can sometimes appearing as "tails" on inclusions or porosity.Discontinuities in TIG weldsThe following discontinuities are peculiar to the TIG welding process. These discontinuities occur in most metals welded by the process including aluminum and stainless steels. The TIG method of welding produces a clean homogeneous weld which when radiographed is easily interpreted.Tungsten inclusions. 夹钨Tungsten is a brittle and inherently dense material used in the electrode in tungsten inert gas welding. If improper welding procedures are used, tungsten may be entrapped in the weld. Radiographically, tungsten is more dense than aluminum or steel; therefore, it shows as a lighter area with a distinct outline on the radiograph.Oxide inclusions夹氧化物are usually visible on the surface of material being welded (especially aluminum). Oxide inclusions are less dense than the surrounding materials and, therefore, appear as dark irregularly shaped discontinuities in the radiograph.Discontinuities in Gas Metal Arc Welds (GMAW)The following discontinuities are most commonly found in GMAW welds.Whiskers are short lengths of weld electrode wire, visible on the top or bottom surface of the weld or contained within the weld. On a radiograph they appear as light, "wire like" indications.Burn through (icicles) results when too much heat causes excessive weld metal to penetrate the weld zone. Lumps of metal sag through the weld creating a thick globular condition on the back of the weld. On a radiograph, burn through appears as dark spots surrounded by light globular areas.welld-02 (Incomplete Root Fusion、根部未熔合)....welld-03 (Insuffucient Reinforcement、增强高) ....welld-04 (Excess Root Penetration、根部焊瘤) ....welld-05 (External Undercut、外部咬肉) ....welld-06 (Internal Undercut、部咬肉) ....welld-07 (Root Concavity、根部凹陷) ....welld-08 (Burn Through、烧穿) ....welld-09 (Isolated Slag Inclusion、单个的夹渣) ....welld-10 (Wagon Track - Slag Line、线状夹渣) ....welld-11 (Interrun Fusion、部未熔合) ....welld-12 (Lack of Sidewall Fusion、侧未熔合) ....welld-13 (Porosity、气孔) ....welld-14 (Cluster Porosity、链状气孔) ....welld-15 (Hollow Bead、夹珠) ....welld-16 (Transverse Crack、横向裂纹) ....welld-17 (Centerline Crack、中心线裂纹) ....welld-18 (Root Crack、根部裂纹) ....welld-19 (Tungsten Inclusion)夹钨....。

无损检测射线常见缺陷图集及分析 ppt

无损检测射线常见缺陷图集及分析 ppt

2、折痕
折痕(曝光后)1 折痕(曝光后)2
折痕(曝光后)3
1、折痕(曝光后)的表面现象是什么? 折痕的表征为黑月牙显示,其密度高于邻近的胶片区域(黑度较 高)。 2、折痕(曝光后)产生的原因是什么? 曝光后或冲洗过程中过度(或用力)弯曲胶片都会使胶片出现折痕。 3、这些现象何时可能发生? 折痕(曝光后)通常出现在卸下暗袋或洗片夹时处理胶片不当的情 况下发生。 4、如何检测曝光后的折痕? 将一些胶片曝光,然后有意识地将其卷曲或扭折,冲洗胶片,然后 通过反射光检验胶片,您有可能见到一个或多个月牙状的黑痕。 5、如何可以避免折痕(曝光后)? 严格遵守暗室操作规程,始终小心处理胶片,特别避免手指对胶片 施以任何类型的压 力。
折 痕 曝 光 前
1、折痕的表面现象是什么? 折痕(曝光前)的表征为白月牙状显示,其密度低于邻近的胶片区域(黑度较低)。 2、它们产生的原因是什么? 曝光前弯曲胶片用力过大或过猛都会导致这种类型的折痕。 3、这些现象何时可能发生? 通常出现在从包装盒取出胶片或在曝光前装入暗袋时处理不当的情况下。 4、如何检验曝光前的折痕? 有意识地将某些胶片卷曲或扭折,使其曝光,然后按正常方法冲洗。检验胶片,这时您可 能会在胶片处理不当的地方风到一些颜色较淡的折痕。 5、如何可以避免它们? 严格遵守暗室操作规程,始终小心处理胶片,特别避免手指对胶片施以任何类型的压力。
到静电放电现象。如果您看到冲洗的胶片有锯齿状线条或黑色斑 点,则极有可能是出现了静电曝光斑点。 5、如何可以避免? 在相对湿度大于40%的环境下保存胶片,从包装盒取出胶片时避免 快速滑动或移动胶片。
定 影 液 斑 点
1、它们的表面现象是什么? 由定影液产生的斑点表征为一些小白圆点,其密度较周围胶片区域的密度底。 2、它们产生的原因是什么? 在显影之前,溅出的定影液滴,即使极其微量,都有可能导致产生白色斑点。 3、这些现象何时可能发生? 无论何时,只要有化学污染的存在,都可能会发生这种现象。通常发生最多的 是由于暗室布局不当或冲洗不小心引起。 4、如何可以避免它们? 保证胶片装卸区域的安全干燥清洁,不能让定影液溅在胶片上。

射线探伤缺陷图谱之未焊透(高清图文并茂,值得收藏)

射线探伤缺陷图谱之未焊透(高清图文并茂,值得收藏)

射线探伤缺陷图谱之未焊透(高清图文并茂,值得收藏)
本图谱根据缺陷性质共分6个章节:
1. 裂纹Cracks
2. 未焊透Lack of Penetration
3. 未熔合Incomplete Fusion
4. 条状缺陷Linear indication
5. 圆形缺陷Rounded indication
6. 伪缺陷Image Artifacts
1. 未焊透Lack of Penetration定义:未焊透是指母材金属之间没有熔化,焊缝金属没有进入接头的根部造成的缺陷。

影像特征:未焊透的典型影像是细直黒线,两侧轮廓都很整齐,为坡口钝边痕迹,宽度恰好为钝边的间隙宽度。

有时坡口钝边有部分溶化,影像轮廓就变得不很整齐,线宽度和黑度局部发生变化,但只要能判断是处于焊缝根部的线性缺陷,仍判定为未焊透。

未焊透有底片上处于焊缝根部的投影位置,一般在焊缝中部,因透照偏、焊偏等原因也可能偏向一侧。

未焊透呈断续或连续分布,有时能贯穿整张底片。

无损检测射线常见缺陷图集及分析资料

无损检测射线常见缺陷图集及分析资料

未融合
边缘未融合
注意:砂轮片磨伤痕迹(不是未融合)
5、裂纹
定义:裂纹是指材料局部断裂形成的缺陷。 影像特征:底片上裂纹和典型影像是轮廓分明的黑线或黑丝。其细节 特征包括:黑线或黑丝上有微小的锯齿,有分叉,粗细和黑度有时有 变化,有些裂纹影像呈较粗的黑线与较细的黑丝相互缠绕状;线的端 部尖细,端头前方有时有丝状阴影延伸。
夹渣
气孔
密集气孔
夹钨
2、条形缺陷 定义:不属于裂纹、未焊透和未熔合的缺陷,当缺陷的长宽比大于3
时,定义为条状缺陷,包括条渣和条孔。
3、未焊透 定义:未焊透是指母材金属之间没有熔化,焊缝金属没有进入 接头的部位根部造成的缺陷。 影像特征:未焊透的典型影像是细直黑线,两侧轮廓都很整齐, 为坡口钝边痕迹,宽度恰好是钝边的间隙宽度。 有时坡口钝边有部分融化,影像轮廓就变得不很整齐,线宽度 和黑度局部发生变化,但只要能判断是出于焊缝根部的线性缺 陷,仍判定为未焊透。 未焊透有底片上处于焊缝根部的投影位置,一般在焊缝中部, 因透照偏、焊偏等原因也可能偏像一侧。 未焊透呈断续或连续分布,有时能贯穿整张底片。
折 痕 曝 光 前
1、折痕的表面现象是什么? 折痕(曝光前)的表征为白月牙状显示,其密度低于邻近的胶片区域(黑度较低)。 2、它们产生的原因是什么? 曝光前弯曲胶片用力过大或过猛都会导致这种类型的折痕。 3、这些现象何时可能发生? 通常出现在从包装盒取出胶片或在曝光前装入暗袋时处理不当的情况下。 4、如何检验曝光前的折痕? 有意识地将某些胶片卷曲或扭折,使其曝光,然后按正常方法冲洗。检验胶片,这时您可 能会在胶片处理不当的地方风到一些颜色较淡的折痕。 5、如何可以避免它们? 严格遵守暗室操作规程,始终小心处理胶片,特别避免手指对胶片施以任何类型的压力。

无损检测射线常见缺陷图集及分析.

无损检测射线常见缺陷图集及分析.

折 痕 曝 光 前
1、折痕的表面现象是什么? 折痕(曝光前)的表征为白月牙状显示,其密度低于邻近的胶片区域(黑度较低)。 2、它们产生的原因是什么? 曝光前弯曲胶片用力过大或过猛都会导致这种类型的折痕。 3、这些现象何时可能发生? 通常出现在从包装盒取出胶片或在曝光前装入暗袋时处理不当的情况下。 4、如何检验曝光前的折痕? 有意识地将某些胶片卷曲或扭折,使其曝光,然后按正常方法冲洗。检验胶片,这时您可 能会在胶片处理不当的地方风到一些颜色较淡的折痕。 5、如何可以避免它们? 严格遵守暗室操作规程,始终小心处理胶片,特别避免手指对胶片施以任何类型的压力。
未融合
边缘未融合
注意:砂轮片磨伤痕迹(不是未融合)
5、裂纹
定义:裂纹是指材料局部断裂形成的缺陷。 影像特征:底片上裂纹和典型影像是轮廓分明的黑线或黑丝。其细节 特征包括:黑线或黑丝上有微小的锯齿,有分叉,粗细和黑度有时有 变化,有些裂纹影像呈较粗的黑线与较细的黑丝相互缠绕状;线的端 部尖细,端头前方有时有丝状阴影延伸。
纵向裂纹
根部裂纹
横向裂纹
6、咬边
一、常见缺陷及示意图
二、其他几种缺陷 三、常见伪缺陷
表 面 内 边
内 咬 边
错 口
接 头 凹 坑
一、常见缺陷及示意图
二、其他几种缺陷 三、常见伪缺陷
1、压痕
1、压痕的表面现象是什么? 压痕的表征为密度明显低于邻近区域的密度。 2、它们产生的原因是什么? 在曝光前某个胶片区域局部受力严重。 3、这些现象何时可能发生? 产生压痕的主要原因在于暗袋准备过程中胶片处理的 方式不当。在处理过程中,胶片某处可能被压(夹)紧 在暗袋中。掉落到暗袋上的物体同样可能造成压痕。 4、如何检验压痕? 直接从同一包装盒中小心准备另一暗袋胶片,曝光并冲 洗胶片,如果未见到与第一次所见一样的暇疵,则第一次所 见的斑痕很可能就是压痕。 5、如何可以避免压痕? 严格遵守暗室操作规程,始终小心处理胶片,避免对胶 片施以任何类型的压力。

射线探伤焊接缺陷显示特点

射线探伤焊接缺陷显示特点

工业X射线电视法 屏 幕 形貌同左的灰白色条纹 形貌同左的灰白色条纹 形貌同左的灰白色条纹 位置与形貌同左的灰白色条纹 分布同左的灰白色图象 灰白色直线状显示 亮度较均匀的长条灰白色图象 黑色块状 灰白色点状
裂 纹
纵向裂纹 放射裂纹 弧坑裂纹
未熔 合和 未焊 透 夹渣
未熔合 未焊透 条状夹渣 夹钨 点状夹渣 球形气孔
圆 形 缺 陷
均布及局部密集 气孔 链状气孔 柱状气孔 斜针状气孔(螺 孔、虫形孔) 表面气孔 弧坑缩孔 咬边 缩沟 焊缝超高
形 状 缺 陷
பைடு நூலகம்
下塌 焊瘤 错边
焊缝一侧与另一侧的黑度值不同,有一明显界限
状 缺 陷 下垂 烧穿 缩根 电弧擦伤 其 他 缺 陷 飞溅 表面撕裂 磨痕 凿痕 焊缝表面的凹槽,黑度值较高的一个区 域 单面焊,背部焊道由于熔池塌陷形成孔 洞,在底片上为黑色影象 单面焊,背部焊道正中的沟槽,呈黑色 影象 母材上的黑色影象 灰白色圆点 黑色条纹 黑色影象 黑色影象 分布同左,但亮度较高 灰白色显示 灰白色显示 灰白色显示 黑色圆点 灰白色条纹 灰白色显示 灰白色显示
焊接缺陷显示特点 焊接缺陷 种类
1
名称 横向裂纹
射线照相法 底 片 与焊缝方向垂直的黑色条纹 与焊缝方向一致的黑色条纹,两头尖细 由一点辐射出去星形黑色条纹 弧坑中纵、横向及星形黑色条纹 坡口边缘、焊道之间以及焊缝根部等处 的伴有气孔或夹渣的连续或断续黑色影 焊缝根部钝边位熔化的直线黑色影象 黑度值较均匀的呈长条黑色不规则影象 白色块状 黑色点状
黑度值中心较大边缘较小且均匀过度的 黑度值中心较小,边缘较大,且 圆形黑色影象 均匀过渡的圆形灰白色显示 均匀分布及局部密集的黑色点状影象 与焊缝方向平行的成串并呈直线状的黑 色影象 黑度极大且均匀的黑色圆形显示 单个或呈人字分布的带尾黑色影象 黑度值不高的圆形影象 指焊道末端的凹陷,为黑色显示 位于焊缝边缘与焊缝走向一直的黑色条 纹 单面焊,背部焊道两侧的黑色影象 焊缝正中的灰白色突起 单面焊,背部焊道正中的灰白色影象 焊缝边缘的灰白色突起 形貌同左的灰白色影象 方向与形貌同左的灰白色影象 亮度极高的白色圆形显示 形貌同左的灰白色图案 亮度不太高的圆形显示 呈灰白色图象 灰白色条纹 灰白色图象 焊缝正中的黑色凸起 分布同左的黑色图象 黑色突起

射线检测-焊缝缺陷图谱

射线检测-焊缝缺陷图谱

1.外部缺陷在焊缝的表面,用肉眼或低倍放大镜就可看到,如咬边,焊瘤,弧坑,表面气孔和裂纹等。

2.内部缺陷位于焊缝内部,必须通过各种无损检测方法或破坏性试验才能发现。

内部缺陷有未焊透,未熔合,夹渣,气孔,裂纹等,这些缺陷是我们无损检测人员检查的主要对象。

焊缝缺陷的危害性:1、由于缺陷的存在,减少了焊缝的承载截面积,削弱了静力拉伸强度。

2、由于缺陷形成缺口,缺口尖端会发生应力集中和脆化现象,容易产生裂纹并扩展。

3、缺陷可能穿透焊缝,发生泄漏,影响致密性。

焊缝纵向裂纹示意图一、焊缝纵向裂纹X光底片焊缝纵向裂纹1 焊缝纵向裂纹2焊缝纵向裂纹3 焊缝纵向裂纹4焊缝纵向裂纹5 焊缝纵向裂纹6焊缝纵向裂纹7 焊缝纵向裂纹8焊缝纵向裂纹9 焊缝纵向裂纹10焊缝纵向裂纹11 焊缝纵向裂纹12焊缝纵向裂纹13 焊缝纵向裂纹14焊缝纵向裂纹15 焊缝纵向裂纹16焊缝纵向裂纹17 焊缝纵向裂纹18焊缝纵向裂纹19 焊缝纵向裂纹20 纵向裂纹的表面特征是沿焊缝长度方向出现的黑线,它既可以是连续线条,也可以是间断线条。

纵向裂纹影像产生的原因是沿焊缝长度破裂而导致的不连续黑线。

二、热影响区纵向裂纹X光底片热影响区纵裂1 热影响区纵裂2 热影响区撕裂呈线性黑色锯齿状,平行于熔合线,穿晶扩展,表面无明显氧化色彩,属脆性断口的延迟裂纹。

焊缝横向裂纹示意图三、焊缝横向裂纹X光底片焊缝横向裂纹1 焊缝横向裂纹25焊缝横向裂纹3 焊缝横向裂纹4焊缝横向裂纹的表征是横在焊接影像上的一根细小黑线(直线或曲线),它产生的原因是由焊缝上的金属破裂引起的。

当焊接应力为拉应力并与氢的析集和淬火脆化同时发生时,极易产生冷裂纹。

四、母材裂纹X光底片母材裂纹1 母材裂纹2裂纹:材料局部断裂形成的缺陷。

裂纹的分类方法:按延伸方向可分为纵向裂纹、横向裂纹、辐射状裂纹;按发生部位可分为焊缝裂纹、热影响区裂纹、熔合区裂纹、焊趾裂纹、弧坑裂纹、母材裂纹;按发生条件和时机可分为热裂纹、冷裂纹、再热裂纹。

射线检测典型缺陷

射线检测典型缺陷

射线检测典型缺陷
缺陷名称:裂纹
焊接裂纹是指金属在焊接应力及其它致脆因素共同作用下,焊接接头中局部地区金属结合力遭到破坏,形成的新界面所产生的缝隙, 有尖锐的缺口和长宽比大的特征, 是焊接结构(件)中最危险的缺陷。

裂纹缺陷X射线底片
缺陷名称:气孔
焊接时熔池中的气泡在凝固时未能逸出而残留下来所形成的空穴称为气孔。

气孔有时以单个出现,有时以成堆的形式聚集在局部区域,其形状有球形、条虫形等。

密集气孔缺陷X射线底片
缺陷名称:夹渣
焊后残留在焊缝中的熔渣称为夹渣,形状较复杂,一般有线状、长条状、颗粒状等。

主要发生在坡口边缘和
每层焊道之间非圆滑过渡的部位,焊道形状发生突变或存在深沟的部位也容易产生夹渣。

条状夹渣缺陷X射线底片
缺陷种类:未熔合
在焊缝金属和母材之间或焊道金属与焊道金属之间末完全熔化结合的部分称为未熔合,常出现在坡口的侧壁、多层焊的层间及焊缝的根部。

这种缺陷有的间隙很大,与熔渣难以区别,未熔合区末端易产生微裂纹。

未熔合缺陷X射线底片
缺陷种类:未焊透
焊接时,母材金属之间应该熔合而末焊上的部分称为末焊透。

出现在单面焊的坡口根部及双面焊的坡口钝边处。

末焊透易造成较大的应力集中,往往从端部产生裂纹。

未焊透缺陷X射线底片中心指示器未收起造成的底片错误曝光,如下图所示。

焊缝RT底片的评判规律及典型缺陷图谱之欧阳科创编

焊缝RT底片的评判规律及典型缺陷图谱之欧阳科创编

焊缝射线照相底片的评判规律一、探伤人员要评片,四项指标放在先*,底片标记齐又正,铅字压缝为废片。

二、评片开始第一件,先找四条熔合线,小口径管照椭圆,根部都在圈里面。

三、气孔形象最明显,中心浓黑边缘浅,夹渣属于非金属,杂乱无章有棱边。

四、咬边成线亦成点,似断似续常相见,这个缺陷最好定,位置就在熔合线。

五、未焊透是大缺陷,典型图象成直线,间隙太小钝边厚,投影部位靠中间。

六、内凹只在仰焊面,间隙太大是关键,内凹未透要分清,内凹透度成弧线。

七、未熔合它斜又扁,常规透照难发现,它的位置有规律,都在坡口与层间。

八、横裂纵裂都危险,横裂多数在表面,纵裂分布范围广,中间稍宽两端尖。

九、还有一种冷裂纹,热影响区常发现,冷裂具有延迟性,焊完两天再拍片。

十、有了裂纹很危险,斩草除根保安全,裂纹不论长和短,全部都是Ⅳ级片。

十一、未熔和也很危险,黑度有深亦有浅,一旦判定就是它,亦是全部Ⅳ级片。

十二、危害缺陷未焊透,Ⅱ级焊缝不能有,管线根据深和长,容器跟着条渣走**。

十三、夹渣评定莫着忙,分清圆形和条状,长宽相比3为界,大于3倍是条状。

十四、气孔危害并不大,标准对它很宽大,长径折点套厚度,中间厚度插入法。

十五、多种缺陷大会合,分门别类先评级,2类相加减去Ⅰ,3类相加减Ⅱ级。

十六、评片要想快又准,下拜焊工当先生,要问诀窍有哪些,焊接工艺和投影。

注:*四项指标系底片的黑度、灵敏度、清晰度、灰雾度必须符合标准的要求。

**指单面焊的管线焊缝和双面焊的容器焊缝内未焊透的判定标准。

Radiograph Interpretation - WeldsIn addition to producing high quality radiographs, the radiographer must also be skilled in radiographic interpretation. Interpretation of radiographs takes place in three basic steps which are (1) detection, (2) interpretation, and (3) evaluation. All of these steps make use of the radiographer's visual acuity. Visual acuity is the ability to resolve a spatial pattern in an image. The ability of an individual to detect discontinuities in radiography is also affected by the lighting condition in the place of viewing, and the experience level for recognizing various features in the image. The following material was developedto help students develop an understanding of the types of defects found in weldments and how they appear in a radiograph.DiscontinuitiesDiscontinuities are interruptions in the typical structure of a material. These interruptions may occur in the base metal, weld material or "heat affected" zones. Discontinuities, which do not meet therequirements of the codes or specification used to invoke and control an inspection, are referred to as defects.General Welding DiscontinuitiesThe following discontinuities are typical of all types of welding.Cold lap is a condition where the weld filler metal does not properly fuse with the base metal or the previous weld pass material (interpass cold lap). The arc does not melt the base metal sufficiently and causes the slightly molten puddle to flow into base material without bonding. Porosity气孔is the result of gas entrapment in the solidifying metal. Porosity can take many shapes on a radiograph but often appears as dark round or irregular spots or specks appearing singularly, in clusters or rows. Sometimes porosity is elongated and may have the appearance of having a tail This is the result of gas attempting to escape while the metal is still in a liquid state and is called wormhole porosity. All porosity is a void in the material it will have a radiographic density more than the surrounding area..Cluster porosity链状气孔is caused when flux coated electrodes are contaminated with moisture. The moisture turns into gases when heated and becomes trapped in the weld during the welding process. Cluster porosity appear just like regular porosity in the radiograph but the indications will be grouped close together.Slag inclusions夹渣 are nonmetallic solid material entrapped in weld metal or between weld and base metal. In a radiograph, dark, jagged asymmetrical shapes within the weld or along the weld joint areas are indicative of slag inclusions.Incomplete penetration (IP) or lack of penetration (LOP)未焊透occurs when the weld metal fails to penetrate the joint. It is one of the most objectionable weld discontinuities. Lack of penetration allows a natural stress riser from which a crack may propagate. The appearance on a radiograph is a dark area with well-defined, straightedges that follows the land or root face down the center of the weldment.Incomplete fusion未熔合is a condition where the weld filler metal does not properly fuse with the base metal. Appearance on radiograph: usually appears as a dark line or lines oriented in the direction of the weld seam along the weld preparation or joining area. Internal concavity or suck back内凹或吸入is condition where the weld metal has contracted as it cools and has been drawn up into the root of the weld. On a radiograph it looks similar to lack of penetration but the line has irregular edges and it is often quite wide in the center of the weld image.Internal or root undercut内部或根部咬边is an erosion of the base metal next to the root of the weld. In the radiographic image it appears as a dark irregular line offset from the centerline of the weldment. Undercutting is not as straight edged as LOP because it does not follow a ground edge.External or crown undercut外部或顶部咬边is an erosion of the base metal next to the crown of the weld. In the radiograph, it appears as a dark irregular line along the outside edge of the weld area.Offset ormismatch错边are terms associated with a condition where two pieces being welded together are not properly aligned. The radiographic image is a noticeable difference in density between the two pieces. The difference in density is caused by the difference in material thickness. The dark, straight line is caused by failure of the weld metal to fuse with the land area.Inadequate weld reinforcement未填满is an area of a weld where the thickness of weld metal deposited is less than the thickness of the base material. It is very easy to determine by radiograph if the weld has inadequate reinforcement, because the image density in the area of suspected inadequacy will be more (darker) than the image density of the surrounding base material.Excess weld reinforcement增强余高is an area of a weld, which has weld metal added in excess of that specified by engineering drawings and codes. The appearance on a radiograph is a localized, lighter area in the weld. A visual inspection will easily determine if the weld reinforcement is in excess of that specified by the individual code involved in the inspection.Cracking裂纹can be detected in a radiograph only the crack is propagating in a direction that produced a change in thickness that is parallel to the x-ray beam. Cracks will appearas jagged and often veryfaint irregular lines. Cracks can sometimes appearing as "tails" on inclusions or porosity.Discontinuities in TIG weldsThe following discontinuities are peculiar to the TIG welding process. These discontinuities occur in most metals welded by the process including aluminum and stainless steels. The TIG method of welding produces a clean homogeneous weld which when radiographed is easily interpreted.Tungsten inclusions. 夹钨Tungsten is a brittle and inherently dense material used in the electrode in tungsten inert gas welding. If improper welding procedures are used, tungsten may be entrapped in the weld. Radiographically, tungsten is more dense than aluminum or steel; therefore, it shows as a lighter area with a distinct outline on the radiograph.Oxide inclusions夹氧化物are usually visible on the surface of material being welded (especially aluminum). Oxide inclusions are less dense than the surrounding materials and, therefore, appear as dark irregularly shaped discontinuities in the radiograph.Discontinuities in Gas Metal Arc Welds (GMAW)The following discontinuities are most commonly found in GMAW welds.Whiskers are short lengths of weld electrode wire, visible on the top or bottom surface of the weld or contained within the weld. On a radiograph they appear as light, "wire like" indications.Burn through (icicles) results when too much heat causes excessive weld metal to penetrate the weld zone. Lumps of metal sag through the weld creating a thick globular condition on the back of the weld. On a radiograph, burn through appears as dark spots surrounded by light globular areas.welld-02 (Incomplete Root Fusion、根部未熔合)welld-03 (Insuffucient Reinforcement、增强高)welld-04 (Excess Root Penetration、根部焊瘤)welld-05 (External Undercut、外部咬肉)welld-06 (Internal Undercut、内部咬肉)welld-07 (Root Concavity、根部凹陷)welld-08 (Burn Through、烧穿)welld-09 (Isolated Slag Inclusion、单个的夹渣)welld-10 (Wagon Track - Slag Line、线状夹渣) welld-11 (Interrun Fusion、内部未熔合)welld-12 (Lack of Sidewall Fusion、内侧未熔合) welld-13 (Porosity、气孔)welld-14 (Cluster Porosity、链状气孔)welld-15 (Hollow Bead、夹珠)welld-16 (Transverse Crack、横向裂纹)welld-17 (Centerline Crack、中心线裂纹)welld-18 (Root Crack、根部裂纹)welld-19 (Tungsten Inclusion)夹钨。

射线探伤の评片学习(有图)

射线探伤の评片学习(有图)

射线探伤の评片学习(有图)焊缝评片口诀(1)评片人员应注意, 适用标准要熟记.观片像质放在先, 所有标记要齐全.识别伪象第二件, 仔细区分也不难.气孔图象最易看, 圆形浓黑边缘淡.非金点状夹渣物, 形状不惦有棱边.夹珠通常很少见, 白色底片有黑边.咬边成线或成点, 似断似续常出现.这种缺陷很好评, 位置就在熔合线.未熔合的深度浅, 射线照相难发现.未焊透是大缺陷, 影象大都呈直线.间隙过小饨边厚, 位置就在缝中间.内凹就在仰焊面, 间隙太大是关键.焊缝评片口诀(2)横裂纵裂最危险, 纵向裂纹常相见.有的直线有的弯, 中间稍宽两端尖.裂纹未熔不允许, 若要发现评四级.单面出现未焊透, 应以长深来区分.未熔条渣区分难, 评定两者细心看.夹渣评定测长短, 不能评为一级片.一直线上条渣组, 测量间距是关键.缺陷评级按板厚, 缺陷数量按条款.气孔条渣在一起, 孔渣各自先评级.级别之和再减一, 成为最终评定级.评片综合技能高, 标准规范最重要.定性定量和评级, 最终结论不能少.下面参照几张典型底片和实物示意图,便于大家理解和记忆一、评片前的准备工作1)工具准备:应准备评片尺,记录笔,放大镜,记录表格2)检查评片设备是否完好:二、评片前首先仔细研究提供的信息:1)材料厚度主要评定体积性缺陷体积性缺陷主要分为条状缺陷与圆形缺陷。

长径与短径之比大于3者为条状缺陷,不大于3为圆形缺陷。

对于条状缺陷主要用于评定等级。

级别单个条形缺陷的最大长度一组条形缺陷的累计最大长度Ⅰ不允许Ⅱ≤T/3(最小可为4) 且≤20在长度为12T的任意选定条形缺陷评定区,相邻缺陷间距不超过6L的任一组的累计长度不超过T,但最小可为4Ⅲ≤2T/3(最小可为6)且≤30在长度为6T的任意选定条形缺陷评定区相邻缺陷间距不超过3L的任一组的累计长度不超过T,但最小可为6Ⅳ大于Ⅲ级对于圆形缺陷主要用于缺陷评定区的确定与评定等级评定区10×1010×2010×30母材公称厚度≤10>10~15 >15~20 >25~50 >50~100 >100Ⅰ 1 2 3 4 5 6Ⅱ 3 6 9 12 15 18Ⅲ 6 12 18 24 30 38Ⅳ缺陷点数大于Ⅲ级或缺陷长径大于T/2缺陷长径≤1>1~2 >2~3 >3~4 >4~6 >6~8 >8缺陷点数 1 2 3 6 10 15 25综合评级:在圆形缺陷评定区内同时存在圆形缺陷与条形缺陷,应当进行综合,综合评级的级别为圆形缺陷评定级别加条形缺陷评定级别减一。

无损检测射线常见缺陷图集及分析-精选文档

无损检测射线常见缺陷图集及分析-精选文档

纵向裂纹
根部裂纹
横向裂纹
6、咬边
一、常见缺陷及示意图
二、其他几种缺陷 三、常见伪缺陷
表 面 内 凹
根 部 内 凹
表 面 咬 边
内 咬 边
错 口
接 头 凹 坑
一、常见缺陷及示意图
二、其他几种缺陷 三、常见伪缺陷
1、压痕
1、压痕的表面现象是什么? 压痕的表征为密度明显低于邻近区域的密度。 2、它们产生的原因是什么? 在曝光前某个胶片区域局部受力严重。 3、这些现象何时可能发生? 产生压痕的主要原因在于暗袋准备过程中胶片处理的 方式不当。在处理过程中,胶片某处可能被压(夹)紧 在暗袋中。掉落到暗袋上的物体同样可能造成压痕。 4、如何检验压痕? 直接从同一包装盒中小心准备另一暗袋胶片,曝光并冲 洗胶片,如果未见到与第一次所见一样的暇疵,则第一次所 见的斑痕很可能就是压痕。 5、如何可以避免压痕? 严格遵守暗室操作规程,始终小心处理胶片,避免对胶 片施以任何类型的压力。
折 痕 曝 光 前
1、折痕的表面现象是什么? 折痕(曝光前)的表征为白月牙状显示,其密度低于邻近的胶片区域(黑度较低)。 2、它们产生的原因是什么? 曝光前弯曲胶片用力过大或过猛都会导致这种类型的折痕。 3、这些现象何时可能发生? 通常出现在从包装盒取出胶片或在曝光前装入暗袋时处理不当的情况下。 4、如何检验曝光前的折痕? 有意识地将某些胶片卷曲或扭折,使其曝光,然后按正常方法冲洗。检验胶片,这时您可 能会在胶片处理不当的地方风到一些颜色较淡的折痕。 5、如何可以避免它们? 严格遵守暗室操作规程,始终小心处理胶片,特别避免手指对胶片施以任何类型的压力。
2、折痕
折痕(曝光后)1
折痕(曝光后)2
折痕(曝光后)3

无损检测射线常见缺陷图集及分析

无损检测射线常见缺陷图集及分析

夹 纸 痕 迹
1、它们的表面现象是什么? 夹纸痕迹的表征为一块低密度区域,并几乎覆盖整张胶片。 2、它们产生的原因是什么? 如果胶片和铅箔增感屏之间存在一张纸,并产生了投影,则会出 现夹纸痕迹。 3、这些现象何时可能发生? 如果没有去掉衬纸,则会发生这种情况。 4、如何检测夹纸痕迹? 只需在有衬纸或无衬纸两种情况下进行曝光检测。 5、如何可以避免它们? 确保在曝光前去掉 折痕(曝光后)2
折痕(曝光后)3
1、折痕(曝光后)的表面现象是什么? 折痕的表征为黑月牙显示,其密度高于邻近的胶片区域(黑度较 高)。 2、折痕(曝光后)产生的原因是什么? 曝光后或冲洗过程中过度(或用力)弯曲胶片都会使胶片出现折痕。 3、这些现象何时可能发生? 折痕(曝光后)通常出现在卸下暗袋或洗片夹时处理胶片不当的情 况下发生。 4、如何检测曝光后的折痕? 将一些胶片曝光,然后有意识地将其卷曲或扭折,冲洗胶片,然后 通过反射光检验胶片,您有可能见到一个或多个月牙状的黑痕。 5、如何可以避免折痕(曝光后)? 严格遵守暗室操作规程,始终小心处理胶片,特别避免手指对胶片 施以任何类型的压 力。
增 感 屏 痕 迹 1、它们的表面现象是什么? 增感屏痕迹的表征为负片上的一条暗纹。增感屏痕迹也可能表征为负片上的白色 斑点。 2、它们产生的原因是什么? 暗纹是由铅箔增感屏上的深擦痕引起的,而亮斑是由铅箔增感屏上的片状杂质引 起的。 3、这些现象何时可能发生? 当铅箔增感屏受到某种程度的擦伤或损坏时,您就会见到铅箔增感屏上的擦痕, 如果有杂质进入上面,也会产生这种现象。 4、如何检测铅箔增感屏上的痕迹? 近距离仔细观察铅箔增感屏,如果发生任何损坏,必须进行更换。如果无法确定 是否有损坏,请用新的铅箔增感屏更换可疑的铅箔增感屏上,然后利用胶片检测。 5、如何可以避免它们? 首先避免擦伤铅箔增感屏,并始终保持工作区域的洁净。另外,如有可能,请使 用铅封包装的胶片形式。
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