15CrMoR合金钢焊接失效分析及预防

Welding-failure analysis and preventive measures of 15CrMoR alloy steel

针对取样于15CrMoR钢的焊接失效部件,通过材料的力学性能和化学成分分析,结合断口的微观形貌,分析该材料焊接失效的原因。结果表明:该15CrMoR钢在焊接过程中氢进入材料内部,加之该材料的力学性能偏脆性,产生了焊接氢致冷裂纹,在碳弧气刨的冲击作用下失效。建议严格控制焊前预热、焊后消氢和整体热处理工艺,并严格控制焊接质量,以减小15CrMoR钢焊接裂纹的产生。

Based on a welding-failed structure collected from 15CrMoR steel in this paper, the failure reasons of pressure vessel were concluded by analyzing the 15CrMoR mechanical properties, chemical composition and fracture morphology. Results showed that hydrogen enter into the interior of the material during the welding process of the 15CrMoR steel, and mechanical properties of the material are brittleness, which led to the welding hydrogen cooling crack and the failure under the carbon arc gouging. It was recommended that strictly controls of preheat treatment,hydrogen elimination treatment and integral heat treatment were needed, meanwhile strictly controls of base metal quality were necessary, which were good approaches to reduce welding cracks of 15CrMoR structures.