材料期刊网

比较了三种不同冶炼工艺(平炉与电炉混合炼钢经RH真空循环脱气处理、碱性电炉冶炼及电炉冶炼加电渣重熔)和两种不同脱氧方法(并用铝、钛或仅用铝脱氧)生产的五炉18Cr2Ni4WA钢的过热敏感性并观察了断口.实验表明,这种钢产生严重过热井出现石状断口的条件是:(1)钢在高温加热时原始奥氏体晶粒充分长大;(2)钢中含有MnS夹杂物以细小的颗粒沉淀在原始奥氏体晶界上,并用铝、钛脱氧使钢中含有微量残留钛可以在高温加热过程中阻止奥氏体晶粒长大同时改善MnS夹杂物的形态和分布状况,从而有效地降低了这种钢的过热敏感性。最后,讨论了这种钢形成石状断口的机构。

The steel (18Cr2Ni4WA) melted by three different processes and deoxidized eitherwith aluminium and titanium or with aluminium alone has been studied in order to clar-ify the cause of its rock-like fractography. It is believed that such rock-like fracture isconnected with the sensibility of over-heating of the steel. Conditions render this steelsensible to over-heating are: (1) the over-growth of austenite grains on heating at hightemperatures; (2) the precipitation of fine manganese sulphide inclusions at the austen-ite boundaries. It is considered that small amounts of residual titanium left over afterdeoxidation may retard the growth of austenite grains as well as modify the mode anddistribution of the fine manganese sulphide inclusions, thus reducing the sensibility toover-heating of the steel.