SA350-Gr·LF3 CL2法兰低温冲击吸收能量不合格的原因分析

Analysis of unqualified reason for SA350-Gr·LF3 CL2 flange’s impact absorbing energy at low temperature

对压力容器用SA350-Gr·LF3 CL2锻件法兰进行-101℃低温冲击试验时,发现其低温冲击吸收能量低于标准要求值。利用化学分析、金相检验、SEM、EDX分析等检验手段对不合格原因进行分析。结果表明,该锻件法兰取样进行模拟焊后热处理试验时,冷却过程中降温过慢,导致显微组织中渗碳体聚集长大,降低了材料的低温冲击吸收能量。

The impact absorption energy at low temperature(-101 ℃) was unqualified,when the mechanics performance of SA350-Gr·LF3 CL2 forgings flange for Pressure Vessels was tested.The unqualified reason was studied by chemical analysis, metallographic examination,SEM, and EDX. The results showed that the cooling velocity were too slower at the process of PWHT experiment for forgings flange’s sample, the cementite was accumulated and grew, the impact absorbing energy at low temperature was reduced at last.