射线探伤-典型缺陷图第五篇-裂纹篇
无损检测射线常见缺陷图集及分析RT射线检测部分
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？ 确保在曝光前去掉全部衬纸。
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。
一、常见缺陷及示意图
二、其他几种缺陷 三、常见伪缺陷
一、常见缺陷
1、圆形缺陷 定义：长宽比小于等于3的非裂纹、未焊透和未熔合缺陷。 圆形缺陷包括气孔、块状夹渣、夹钨等缺陷。气孔
气孔的成像：呈暗色斑点，中心黑度较大,边缘较浅平滑过渡，轮廓较清晰。 夹渣（非金属）的成像：呈暗色斑点，黑度分布无规律，轮廓不圆滑，小点 状夹渣轮廓较不清晰。 夹钨(金属夹渣)成像：呈亮点，轮廓清晰。
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。
管道射线探伤评片图--裂纹18张
重点观察缺陷 裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
LW11
手工
单面
仰焊
根部裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
LW11
手工
单面
仰焊
横向裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
LW11
手工
单面
仰焊 中心纵向裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
其它缺陷
LW05手工单面 Nhomakorabea平
热裂纹
根部未焊透
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
LW03
自动
单面
平
LW08
冷裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
LW11
手工
单面
水平
冷裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
其它缺陷
LW11
手工
单面
仰焊 仰焊收缩裂纹
手工
单面
焊趾裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置 重点观察缺陷
手工
单面
弧坑裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置
重点观察缺陷
其它缺陷
手工
单面
弧坑裂纹扩展纵向裂纹
编号 焊接方法 焊缝型式 焊接位置
手工
单面
重点观察缺陷 角焊缝裂纹
其它缺陷
编号 焊接方法 焊缝型式 焊接位置
手工
单面
编号
焊接方法
焊缝型 式
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。
无损检测射线常见缺陷图集及分析
气孔缺陷定义：在金属材料中气孔是由于熔炼或 浇注过程中气体在金属内部未能全部逸出而形成 的空穴。
气孔缺陷图集展示：展示不同类型的气孔缺陷图 谱包括圆形气孔、椭圆形气孔、链状气孔等。
气孔缺陷产生原因：主要由于金属材料熔 炼或浇注过程中气体在金属内部未能全部 逸出或者由于金属材料中含有易形成气体 的元素所致。
无损检测射线常见缺 陷图集及分析
汇报人：
目录
添加目录标题
无损检测射线技术 简介
常见缺陷图集展示
缺陷图集分析
无损检测射线技术 发展趋势
结论
添加章节标题
无损检测射线技术 简介
通过检测衰减后射线的强度 或透射后的影像进行分析
利用射线穿透物质时产生的 衰减作用进行检测
可用于检测各种材料和产品 内部缺陷
降低维护成本：及时发现设备故障 避免重大事故发生降低维护成本。
添加标题
添加标题
添加标题添ຫໍສະໝຸດ 标题提高生产效率：通过快速检测减少 生产过程中的停机时间提高生产效 率。
促进工业发展：无损检测技术的应 用提高了工业生产的可靠性和安全 性推动了工业的发展。
提高检测精度和可 靠性
降低漏检和误检率
促进缺陷识别和分 类标准化
常见缺陷图集展示
裂纹缺陷定义：裂纹是一种常见的缺陷类型通常是由于材料受到外力作用或内部应力过大而产生的断裂现象。
裂纹缺陷图集展示：展示不同材料、不同形状和尺寸的裂纹缺陷图像以便更好地了解裂纹的形成和分布情况。
裂纹缺陷分析：对裂纹缺陷进行详细分析包括裂纹的形态、走向、大小等方面以便更好地了解裂纹的性质和产生 原因。
缺点：无损检测 射线技术需要使 用放射性物质存 在一定的安全风 险同时检测成本 较高设备也较为 昂贵。
管道射线探伤评片图-裂纹18张
边界清晰
裂纹的边界通常比较清晰，与周围区域有明显的分界线。
密度较高
在某些情况下，裂纹的密度较高，表现为密集的裂纹群。
04
管道射线探伤评片图分析
评片图的解读
评片图解读
评片图是管道射线探伤的重要结果，通过解读评片图，可以了解管 道内部的缺陷情况。
缺陷类型识别
应力集中。
裂纹的处理方法
焊接修复
对于较小的裂纹，可以采用焊 接的方式进行修复，确保裂纹
完全封闭。
更换管段
对于无法修复的严重裂纹或破 损管段，应立即更换，避免问 题扩大。
内衬修复
对于管道内部的裂纹，可以采用 内衬修复技术，在管道内部加装 一层耐腐蚀、耐磨损的材料。
表面涂层
在管道表面涂覆防腐蚀涂层， 延缓裂纹的发展，延长管道使
06
案例分析：18张管道射 线探伤评片图-裂纹展示
案例一：某管道焊缝处的裂纹
总结词
该管道焊缝处的裂纹表现为一条清晰的线性缺陷，可能是由于焊接过程中热影响区处理不当或焊接工艺参数不合 适所导致。
详细描述
在管道焊缝处，通常由于焊接过程中快速加热和冷却，容易在焊缝的热影响区产生应力集中，进而形成裂纹。这 类裂纹通常具有一定的方向性，与焊接方向一致。在射线探伤评片图中，此类裂纹表现为一条清晰、细长的线性 缺陷，具有一定的贯穿性。
随有管壁变形或凹陷的现象。
THANKS
感谢观看
裂纹的识别方法
观察评片图
01
通过观察评片图上的影像，判断是否存在裂纹，并初步判断裂
纹的类型。
放大镜观察
02
对于较小的裂纹，可以使用放大镜进行观察，以更准确地判断
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。
射线检测典型缺陷图_未熔合.[5篇]
![射线检测典型缺陷图_未熔合.[5篇]](https://img.taocdn.com/s3/m/2c13e192f424ccbff121dd36a32d7375a417c611.png)
射线检测典型缺陷图_未熔合.[5篇]第一篇：射线检测典型缺陷图_未熔合.未熔合定义：未熔合是指焊缝金属与母材金属可焊缝金属之间未熔化结合在一起的缺陷。
影像特征：根部未熔合的典型影像是连续或断续的黑线，线的一侧轮廓整齐且黑度较大，为坡口或钝边的痕迹，另一侧轮廓可能较规则，也可能不规则。
根部未熔合在底片上的位置就是焊缝根部的投影位置，一般在焊缝的中间，因坡口形状或投影角度等原因出可能偏向一边。
坡口未熔合的典型影像是连续或断续的黑线，宽度不一，黑度不均匀，一侧轮廓较齐，黑度较大，另一侧轮廓不规则，黑度较小，在底片上的位置一般在中心至边缘的1/2处，沿焊缝纵向延伸。
层间未熔合的典型影像是黑度不大的块状阴影，开关不规则，如伴有夹渣时，夹渣部位黑度较大。
一般在射线照相检测中不易发现。
条状缺陷• 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。
其他缺陷第二篇：高级质检员X射线检测考试典型缺陷图谱分析高级质检员X射线检测考试典型缺陷图谱分析（2）2011.07.29 检验监测中心 FJW提供奥氏体不锈钢的焊接一、奥氏体不锈钢的焊接特点•奥氏体不锈钢是石油化工生产中应用最为广泛的金属材料之一，其焊接性能良好，但在焊接过程中也容易产生不少问题，主要表现为以下几种：1.1 晶间腐蚀奥氏体不锈钢焊接件容易在焊接接头处发生晶间腐蚀，根据贫铬理论，其原因是焊接时焊缝和热影响区在加热到450～850℃温度范围停留一定时间的接头部位，在晶界处析出高铬碳化物（Cr23C6），引起晶粒表层含铬量降低，形成贫铬区，在腐蚀介质的作用下，晶粒表层的贫铬区受到腐蚀而形成晶间腐蚀。
这时被腐蚀的焊接接头表面无明显变化，受力时则会沿晶界断裂，几乎完全失去强度。
•••为防止和减少焊接接头处的晶间腐蚀，一般采取的防止措施有：（1）采用低碳或超低碳的焊材，如A002等，或采用含钛、铌等稳定化元素的焊条，如A137、A132等；（2）由焊丝或焊条向焊缝熔入一定量的铁素体形成元素，使焊缝金属成为奥氏体+铁素体的双相组织（铁素体一般控制4-12％）；（3）减少焊接熔池过热，选用较小的焊接电流和较快的焊接速度，加快冷却速度；（4）对耐晶间腐蚀性能要求很高的焊件进行焊后稳定化退火处理。
射线检测常见缺陷图
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（密集气孔）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, straight edges that follows the land or root face down the center of the weldment.Incomplete fusion（未融合）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）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（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（未焊满）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（焊缝余高过高）is an area of a weld that 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 engineering requirements.Cracks（裂纹）can be detected in a radiograph only when they are propagating in a direction that produces a change in thickness that is parallel to the x-ray beam. Cracks will appear as jagged and often very faint irregular lines. Cracks can sometimes appear 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 andstainless 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 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（烧穿）results when too much heat causes excessive weld metal to penetrate the weld zone. Often lumps of metal sag through the weld creating a thick globular condition on the back of the weld. These globs of metal are referred to as icicles. On a radiograph, burn through appears as dark spots, which are often surrounded by light globular areas (icicles).Radiograph Interpretation – Castings（铸件）The major objective of radiographic testing of castings is the disclosure of defects that adversely affect the strength of the product. Casting are a product form that often receive radiographic inspection since many of the defects produced by the casting process are volumetric in nature and, thus, relatively easy to detect with this method. These discontinuities of course, are related to casting process deficiencies, which, if properly understood, can lead to accurate accept-reject decisions as well as to suitable corrective measures. Since different types and sizes of defects have different effects of the performance of the casting, it is important that the radiographer is able to identify the type and size of the defects. ASTM E155, Standard for Radiographs of castings has been produced to help the radiographer make a better assessment of the defects found components. The castings used to produce the standard radiographs have been destructively analyzed to confirm the size and type of discontinuities present. The following is a brief description of the most common discontinuity types included in existing reference radiograph documents (in graded types or as single illustrations).RADIOGRAPHIC INDICATIONS FOR CASTINGSGas porosity or blow holes are caused by accumulated gas or air which is trapped by the metal. These discontinuities are usually smooth-walled rounded cavities of a spherical, elongated or flattened shape. If the sprue is not high enough to provide the necessary heat transfer needed to force the gas or air out of the mold, the gas or air will be trapped as the molten metal begins to solidify. Blows can also be caused by sand that is too fine, too wet, or by sand that has a low permeability so that gas can't escape. Too high a moisture content in the sand makes it difficult to carry the excessive volumes of water vapor away from the casting. Another cause of blows can be attributed to using green ladles, rusty or damp chills andchaplets.Sand inclusions and dross are nonmetallic oxides, appearing on the radiograph as irregular, dark blotches. These come from disintegrated portions of mold or core walls and/or from oxides (formed in the melt) which have not been skimmed off prior to introduction of the metal into the mold gates. Careful control of the melt, proper holding time in the ladle and skimming of the melt during pouring will minimize or obviate this source of trouble.Shrinkage is a form of discontinuity that appears as dark spots on the radiograph. Shrinkage assumes various forms but in all cases it occurs because molten metal shrinks as it solidifies, in all portions of the final casting. Shrinkage is avoided by making sure that the volume of the casting is adequately fed by risers which sacrificially retain the shrinkage. Shrinkage can be recognized in a number of characteristic by varying appearances on radiographs. There are at least four types: (1) cavity; (2) dendritic; (3) filamentary; and (4) sponge types. Some documents designate these types by numbers, without actual names, to avoid possiblemisunderstanding.Cavity shrinkage appears as areas with distinct jagged boundaries. It may be produced when metal solidifiesbetween two original streams of melt, coming from opposite directions to join a common front; cavity shrinkage usually occurs at a time when the melt has almost reached solidification temperature and there is no source of supplementary liquid to feed possible cavities.Dendritic shrinkage is a distribution of very fine lines or small elongated cavities that mayvary in density and are usually unconnected.Filamentary shrinkage usually occurs as a continuous structure of connected lines orbranches of variable length, width and density, or occasionally as a network.Sponge shrinkage shows itself as areas of lacy texture with diffuse outlines, generallytoward the mid-thickness of heavier casting sections. Sponge shrinkage may bedendritic or filamentary shrinkage; filamentary sponge shrinkage appears more blurredbecause it is projected through the relatively thick coating between the discontinuities and the film surface.Cracks are thin (straight or jagged) linearly disposed discontinuities that occur after the melt has solidified. They generally appear singly and originate at casting surfaces.Cold shuts generally appear on or near a surface of cast metal as a result of two streams of liquid meeting and failing to unite. They may appear on a radiograph as cracks or seams with smooth or rounded edges.Inclusions are nonmetallic materials in a supposedly solid metallic matrix. They may be less or more dense than the matrix alloy and will appear on the radiograph, respectively, as darker or lighter indications. The lattertype is more common in light metal castings.Core shift shows itself as a variation in section thickness, usually on radiographic views representing diametrically opposite portions of cylindrical casting portions.Hot tears are linearly disposed indications that represent fractures formed in a metal during solidification because of hindered contraction. The latter may occur due to overly hard (completely unyielding) mold or core walls. The effect of hot tears, as a stress concentration, is similar to that of an ordinary crack; how tears are usually systematicflaws. If flaws are identified as hot tears in larger runs of a casting type, they may call for explicit improvements in technique.Misruns appear on the radiograph as prominent dense areas of variable dimensions with a definite smooth outline. They are mostly random in occurrence and not readily eliminated by specific remedial actions in the process.Mottling is a radiographic indication that appears as an indistinct area of more or less dense images. The condition is a diffraction effect that occurs on relatively vague,thin-section radiographs, most often with austenitic stainless steel. Mottling is caused by interaction of the object's grain boundary material with low-energy X-rays (300 kV or lower). Inexperienced interpreters may incorrectly consider mottling as indications of unacceptable casting flaws. Even experienced interpreters often have to check the condition by re-radiography from slightly different source-film angles. Shifts in mottling are then very pronounced, while true casting discontinuities change only slightly in appearance.Radiographic Indications for Casting Repair WeldsMost common alloy castings require welding either in upgrading from defective conditions or in joining to other system parts. It is mainly for reasons of casting repair that these descriptions of the more common weld defects are provided here. The terms appear as indication types in ASTM E390. For additional information, see theNondestructive Testing Handbook, Volume 3, Section 9 on the "Radiographic Control of Welds."Slag is nonmetallic solid material entrapped in weld metal or between weld material and base metal. Radiographically, slag may appear in various shapes, from long narrow indications to short wide indications, and in various densities, from gray to very dark. Porosity is a series of rounded gas pockets or voids in the weld metal, and is generally cylindrical or elliptical in shape.Undercut is a groove melted in the base metal at the edge of a weld and left unfilled by weld metal. It represents a stress concentration that often must be corrected, and appears as a dark indication at the toe of a weld.Incomplete penetration, as the name implies, is a lack of weld penetration through the thickness of the joint (or penetration which is less than specified). It is located at the center of a weld and is a wide, linear indication.Incomplete fusion is lack of complete fusion of some portions of the metal in a weld joint with adjacent metal; either base or previously deposited weld metal. On a radiograph, this appears as a long, sharp linear indication, occurring at the centerline of the weld joint or at the fusion line.Melt-through is a convex or concave irregularity (on the surface of backing ring, strip, fused root or adjacent base metal) resulting from complete melting of a localized regionbut without development of a void or open hole. On a radiograph, melt-through generally appears as a round or elliptical indication.Burn-through is a void or open hole into a backing ring, strip, fused root or adjacent base metal.Arc strike is an indication from a localized heat-affected zone or a change in surface contour of a finished weld or adjacent base metal. Arc strikes are caused by the heat generated when electrical energy passes between surfaces of the finished weld or base metal and the current source.Weld spatter occurs in arc or gas welding as metal particles which are expelled during welding and which do not form part of the actual weld: weld spatter appears as many small, light cylindrical indications on a radiograph.Tungsten inclusion is usually denser than base-metal particles. Tungsten inclusions appear most linear, very light radiographic images; accept/reject decisions for this defect are generally based on the slag criteria.Oxidation is the condition of a surface which is heated during welding, resulting in oxide formation on the surface, due to partial or complete lack of purge of the weld atmosphere. Also called sugaring.Root edge condition shows the penetration of weld metal into the backing ring or into the clearance between backing ring or strip and the base metal. It appears in radiographs as asharply defined film density transition.Root undercut appears as an intermittent orcontinuous groove in the internal surface of the base metal, backing ring or strip along the edge of the weld root.Real-time RadiographyReal-time radiography (RTR), or real-time radioscopy, is a nondestructive test (NDT) method whereby an image is produced electronically rather than on film so that very little lag time occurs between the item being exposed to radiation and the resulting image. In most instances, the electronic image that is viewed, results from the radiation passing through the object being inspected and interacting with a screen of material that fluoresces or gives off light when the interaction occurs. The fluorescent elements of the screen form the image much as the grains of silver form the image in film radiography. The image formed is a "positive image" since brighter areas on the image indicate where higher levels of transmitted radiation reached the screen. This image is the opposite of the negative image produced in film radiography. In other words, with RTR, the lighter, brighter areas represent thinner sections or less dense sections of the test object.Real-time radiography is a well-established method of NDT having applications in automotive, aerospace, pressure vessel, electronic, and munition industries, among others. The use of RTR is increasing due to a reduction in the cost of the equipment and resolution of issues such as the protecting and storing digital images. Since RTR is being used increasingly more, these educational materials were developed by the North Central Collaboration for NDT Education (NCCE) to introduce RTR to NDT technician students.Real-time Radiography: An Introductory Course Module for NDT StudentsDownload PDF File。
管道射线探伤评片图--裂纹18张
其它缺陷
编号
焊接方法
焊缝型式 焊接位置
重点观察缺陷
其它缺陷
手工
单面
裂纹
其它缺陷
LW11
手工
单面
LW11
焊接方法 手工
焊缝型式 焊接位置 单面 仰焊
重点观察缺陷 根部裂纹
其它缺陷
编号
LW11
焊接方法 手工
焊缝型式 焊接位置 单面 仰焊
重点观察缺陷 横向裂纹
其它缺陷
编号
LW11
焊接方法 手工
焊缝型式 焊接位置 单面 仰焊
重点观察缺陷 中心纵向裂纹
其它缺陷
编号
焊接方法 手工
焊缝型式 焊接位置 单面
重点观察缺陷 焊趾裂纹
其它缺陷
编号
焊接方法 手工
焊缝型式 焊接位置 单面
重点观察缺陷 弧坑裂纹
其它缺陷
编号
焊接方法 手工
焊缝型式 焊接位置 单面
重点观察缺陷 弧坑裂纹扩展纵向裂纹
其它缺陷
编号
焊接方法 手工
焊缝型式 焊接位置 单面
重点观察缺陷 角焊缝裂纹
编号
LW01
焊接方法
焊缝型 式
焊接位置
重点观察缺陷
其它缺陷
自动
双面
平
热裂纹(在纵缝上)
编号
LW13 LW15
焊接方法 自动＋手工
焊缝型式 双面
焊接位置 平
重点观察缺陷 热裂纹
其它缺陷
编号
LW06 LW14
焊接方法 自动 自动＋手工
焊缝型式 焊接位置 双面 平
重点观察缺陷 横向热裂纹
其它缺陷
编号
LW05
焊接方法 手工
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
X射线照相图谱
五、夹渣性缺陷
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图42 夹渣、密集气孔
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图43 条状夹渣
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图44 夹渣
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图45 夹渣、气孔
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图46 夹渣
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图47 条状夹渣
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ቤተ መጻሕፍቲ ባይዱ
图48 气态夹渣
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图49 夹渣、气孔
目录
前言 一、裂纹性缺陷 二、未焊透性缺陷 三、未熔合性缺陷 四、钨夹渣性缺陷 五、夹渣性缺陷 六、气孔性缺陷
第1页/共85页
前言
《钢制对接焊缝缺陷X射线照相参考图谱》是在大量 焊缝和焊接试件X射线照相实验基础上，经过几年的 搜集、积累，从数千张底片中筛选出具有各种典型缺 陷的底片，经特殊拷贝翻版，由洗印在相纸中的正片 进行排版组谱精装而成。《图谱》中的焊接缺陷，包 括有各种典型裂纹，未焊透、未熔合、夹渣、夹钨和 气孔。
图13 微裂纹
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图14 横向裂纹
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二、未焊透性缺陷
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图15 焊缝边缘未焊透
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图16 未焊透
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图17 未焊透
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图18 未焊透、气孔
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图19 焊缝边缘未焊透
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图20 未焊透、气孔
图35 连续未熔合
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图36 坡口两侧母材与焊肉未熔合
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四、钨夹渣性缺陷
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图37 钨夹渣
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射线检测的缺陷影像分析
射线检测的缺陷影像分析
缺陷性质分为： 1.裂纹、 2.未熔合、 3.未焊透、 4.条形缺陷 5.圆形缺陷，
射线检测的缺陷影像分析—————裂纹①
1. 裂纹 定义：裂纹是指材料局部断裂形成的缺陷。 裂纹有多种分类方法：按延伸方向可分为
纵向裂纹、横向裂纹、辐射状裂纹等；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、焊道下裂纹、弧坑裂纹等； 按发生条件和时机可分为热裂纹、冷裂纹、再 热裂纹等。
对于低碳钢和低合金钢，大致在300℃～200℃以 下。冷裂纹可以焊后立即出现，也有可能在几个 小时，几天甚至更长时间以后发生，这种冷裂纹 称为延迟裂纹，具有更大的危害性。
射线检测的缺陷影像分析—————裂纹⑥
冷裂纹 延迟裂纹多发生在热影响区，少数发生在
焊缝上，沿纵向和横向都有发生。焊趾裂纹、 焊道下裂纹、根部裂纹都是延迟裂纹常见的形 态。
射线检测的缺陷影像分析
————裂纹
射线检测的缺陷影像分析
————裂纹
射线检测的缺陷影像分析
————裂纹
射线检测的缺陷影像分析
————裂纹
射线检测的缺陷影像分析
————裂纹
射线检测的缺陷影像分析
————裂纹
射线检测的缺陷影像分析—————裂纹⑤
冷裂纹 一般在焊后冷却至马氏体转变温度以下产生，
线或其他不规则的。气孔的轮廓比较圆滑，其黑 度中心较大，至边缘减小。
射线检测的缺陷影像分析
————气孔
射线检测的缺陷影像分析
————气孔
射线检测的缺陷影像分析
————气孔
射线检测的缺陷影像分析
————气孔
射线检测的缺陷影像分析
————气孔