奥氏体不锈钢夹杂物控制工艺技术探讨

Discussion of austenitic stainless steel inclusion control technology

奥氏体不锈钢中的夹杂物影响钢材的抗腐蚀性能,对塑性、韧性和抗疲劳性能均有不利的影响。叙述了中航上大高温合金材料有限公司采用EAF＋AOD＋LF生产奥氏体不锈钢时夹杂物控制的主要工艺,分析了夹杂物的主要来源与产生机理,工艺设计时对冶炼过程夹杂物的控制进行了系统的策划。通过加强原辅材料控制,优化AOD脱氧制度,LF精炼采用钙处理和弱搅拌工艺对夹杂物进行变性处理,模铸浇注采用氩气保护浇注等技术手段,最终实现了钢中各类夹杂物含量的降低和稳定控制,满足了核电、压力容器等高端不锈钢管坯的质量要求。

The inclusions in austenitic stainless steel impact on the corrosion resistant performance of the steel,as well as the plasticity,toughness and fatigue resistance.The technology of EAF＋LF＋AOD adopted by the AVIC Shangda High Temperature Alloy Material Co.,Ltd.for controlling the austenitic stainless steel inclusion is introduced.The main source and production mechanism of inclusions are analyzed,and the control of the inclusion of smelting process is systematically planned in the process design.By strengthening the raw material control,optimizing AOD deoxidizing system,applying the calcium treatment and weak mixing process in LF refining to modify the inclusion,and adopting the technology of argon protecting pouring in the casting pouring,the decrease and steady control of the content of inclusions in steel are finally realized,which can meet the quality requirements of nuclear power station,pressure vessel and other high-end stainless steel tube billets.