AISI8630钢泥浆泵排出缸失效分析及工艺改进

针对AISI8630钢锻件在实际生产中出现的锻造失效问题进行了研究。采用"EAF→LF→VD→铸锭"工艺冶炼AISI8630钢锭,钢锭锻造成泥浆泵锻件,经热处理加工后探伤发现密集性缺陷。通过化学成分、低倍分析和金相显微分析,对产生的缺陷进行分析研究。结果表明:宏观检测受检面有许多裂纹,将裂纹打开,发现断口存在明显的白点缺陷;近裂纹附近有灰色硫化物夹杂,存在明显的组织偏析现象,远离裂纹处的金相组织无明显差异。通过加强冶炼过程控制,对钢锭进行锻前消氢、消应力退火及锻后250℃以下缓冷处理等工艺优化,避免了白点缺陷的形成,并经现场验证得到合格产品。

Failure analysis and process improvement on discharge tank of slurry pump for AISI8630 steel

The forging failure problem of AISI8630 steel forgings in actual production was studied. The metallurgical process flow of AISI8630 steel ingot was EAF→ LF→ VD→ casting ingot. The ingot was forged into slurry pump forgings,and the density defects were found by ultrasonic examination after heat treatment. The defects were studied by chemical analysis and macro-analysis and metallographic microscopic analysis. The results show that there are many micro cracks and obvious flake defect on crack fracture in tested surface by macroscopical examination. Gray sulphide inclusions near the cracks and obvious tissue segregation exists,but there is no obvious difference in microstructure away from the crack. The qualified forgings are obtained and the flake defect are avoided throught strictly controlling of the metallurgical process,optimization on the process of dehydrogenation,destress annealing of ingot and cooling treatment below 250 ℃ after forging.