摘要
介绍了高镍奥氏体球墨铸铁排气歧管铸件的结构及首次交付的样件在试验中的断裂问题,通过生产试验,验证了排气歧管断裂的原因是在浇注过程中不进行随流孕育,导致铸件金相中产生碎块状石墨,使铸件力学性能下降,加速了铸件开裂失效的风险。最后指出:(1)高镍奥氏体球墨铸铁件在生产过程中,除了保证球化处理严格按照工艺要求外,在浇注过程中还必须进行随流孕育;(2)在保证球化处理过程符合工艺要求的前提下,随流孕育会进一步增加铁液在凝固过程中石墨结晶的核心,增加共晶团数,避免碎块石墨的产生。
An introduction was made on the structure of high Ni austenite nodular iron exhaust manifold,and the fracture problem occurring during test of the first-delivered sample.Through production test,it was validated that the fracture reason of the exhaust manifold was that since stream inoculation being not conducted during the pouring process and thereby caused chunky graphite and caused mechanical properties decreasing and accelerating risk of casting cracking and failure.Finally pointed out:(1)Beside strictly complying with the process requirements during production process of high Ni austenite nodular iron,it was also needed to conduct stream inoculation.(2)Under the precondition to ensure the nodularizing process meeting requirements,stream inoculation could further increase graphite crystallizing nucleus,increase eutectic cell number,avoid chunky graphite formation.
作者
刘铭
张成
张君
LIU Ming;ZHANG Cheng;ZHANG Jun(Xixia Intake&Exhaust Manifold Co.,Ltd.,Nanyang 474500,China)
出处
《现代铸铁》
CAS
2024年第1期1-4,共4页
Modern Cast Iron
关键词
球墨铸铁
高镍
随流孕育
碎块状石墨
nodular iron
high nickel
stream inoculation
chunky graphite
