复合钢板容器焊缝裂纹的原因分析

ANALYSIS AND RESEARCH TO THE CAUSES OF WELDING LINE CRACK FOR THE CONTAINER MADE OF SHEET ALLOY

某预加氢反应器筒体系采用复合钢板制成,在服役过程中,经无损检查发现筒体环焊缝处存在多处内部裂纹。为了寻求裂纹产生的原因,检测了反应器筒体基层与复层材料的化学成分和力学性能;分析了反应器筒体的焊接工艺参数和焊后热处理工艺参数;计算了筒体材料的焊接冷裂纹敏感性指数;得出了导致反应器筒体焊缝开裂的主要因素是焊前预热温度偏低、焊后高温回火保温时间不足以及复合钢板过渡层焊接的复杂性;提出了可供类似设备制造参考的焊接和焊后热处理工艺参数。

Some container of hydrogenous reactor is made of sheet alloy. Many cracks are found in the welding line during employ. The following researches are done to investigate causes of crack. The mechanical properties and chemic composition of container are checked and measured; jointing and heat treatment technologic parameters for the container are analyzed; the sensitivity exponent of weld crack is calculated. The key factors that caused crack of reactor container are: warm-up temperature too low before welding, heat preservation time too short of high temperature temper, the welding complex of transition layer. The paper also put forward the heat treatment technologic parameters for the container.