Welding Defects Guide 中英对照翻译（焊接缺陷指南）

原文：Common welding defects, their causes, effects and how to identify them.

译文：常见焊接缺陷、产生原因、影响以及检测识别方法

① Porosity 气孔

What is it? 定义

- Small holes or voids in the weld metal caused by trapped gas.

- 焊缝金属内部由于气体滞留形成的小孔或空洞

Common Causes: 常见成因

- Moisture, oil, rust on base metal → 母材表面有水、油污、锈蚀

- Inadequate shielding gas (MIG/TIG) → 保护气不足（熔化极/钨极氩弧焊）

- Improper gas flow rate → 气体流量不合适

- Contaminated filler wire / electrode → 填充焊丝/焊条被污染

Effects: 造成的影响

- Reduces strength → 降低焊缝强度

- Can cause leaks (pressure vessels / piping) → 压力容器、管道发生泄漏

- Poor appearance → 外观成型差

- May lead to corrosion → 容易诱发腐蚀

How to identify? 检测方式

- Visual inspection → 目视检测 VT

- Dye penetrant / Radiography → 渗透检测 PT / 射线检测 RT

- UT (for critical joints) → 超声检测 UT（重要接头）

② Crack 裂纹

What is it? 定义

- A fracture in the weld or HAZ (Heat Affected Zone).

- 发生在焊缝或者热影响区(HAZ)的断裂

Common Causes: 常见成因

- High residual stress → 较高的残余应力

- Improper welding procedure → 焊接工艺不当

- Low preheat / wrong filler → 预热不足 / 填充材料选错

- Rapid cooling → 冷却速度过快

- Poor joint design → 接头设计不合理

Effects: 造成的影响

- Severe reduction in strength → 强度大幅下降

- Can lead to failure under load → 承载时直接失效

- May propagate over time → 裂纹会随时间扩展延伸

- High risk in pressure systems → 在承压设备中属于高风险缺陷

How to identify? 检测方式

- Visual inspection (sometimes visible) → 目视检测（部分肉眼可见）

- Dye penetrant (surface cracks) → 渗透检测（表面裂纹）

- Magnetic particle (ferromagnetic) → 磁粉检测 MT（铁磁性材料）

- UT / Radiography (internal cracks) → 超声UT / 射线RT（内部埋藏裂纹）

③ Undercut 咬边

What is it? 定义

- A groove or depression along the toe of the weld, where base metal is removed.

- 在焊缝焊趾位置形成的沟槽/凹陷，母材被电弧熔化后未得到填充

Common Causes: 常见成因

- Excessive welding current → 焊接电流过大

- High travel speed → 焊接行走速度太快


- Improper electrode angle → 焊枪/焊条角度不对

- Lack of filler metal → 填充金属供给不足

Effects: 造成的影响

- Reduces cross-sectional area → 减小接头有效承载截面积

- Weakens the joint → 削弱接头力学性能

- Can start cracks → 会成为裂纹萌生起源

- May lead to leakage → 可能引发泄漏

How to identify? 检测方式

- Visual inspection (edge groove) → 目视检测（边缘沟槽）

- Dye penetrant (surface) → 渗透检测（表面）

- UT (for critical applications) → 超声检测（重要工况）

Quick Comparison 快速对比表



Prevention Tips 预防要点

✅ Use clean, dry base material → 使用清洁干燥母材

✅ Maintain proper welding parameters → 保持合适焊接参数

✅ Use correct filler / electrode → 选用匹配的填充材料

✅ Ensure proper shielding gas → 保证保护气供给

✅ Follow WPS / qualified procedure → 严格按照WPS评定工艺施焊

右上角 Good Weld 优质焊缝：

- Stronger 强度更高

- Safer 安全性更好

- Longer Life 使用寿命更长