为改善高强度钢的塑性和韧性,对同一种低合金高强度钢进行两种不同回火方式的调质处理,淬火＋缓慢加热回火的传统调质与淬火＋感应加热回火的新调质工艺,分析该工艺对钢的组织与性能的影响.利用扫描电镜和透射电镜观察组织及析出物的变化,采用X射线衍射仪分析了钢中残余奥氏体体积分数.结果表明：两种工艺下,钢的组织均为板条宽300～500 nm左右的马氏体组织,感应加热回火调质工艺处理后,板条组织明显,析出物大多约为20 nm,比传统调质处理后的细小;两种不同热处理工艺均能提高钢的屈服强度.感应加热至500℃回火后试验钢具有16%以上的延伸率,-40℃冲击功达到32 J,优于传统调质工艺处理钢板的综合性能.感应加热回火能获得更多小尺寸析出物和更多的残余奥氏体,有利于改善钢的塑性和韧性.%To improve the plasticity and toughness,two kinds of quenching and tempering process（slow heating rate tempering and induction heating tempering） were used for a high strength low alloy steel.The effect of process on the microstructure and properties of the steel was studied.Microstructure and precipitates were investigated by SEM and TEM,and the retained austenite volume fraction was measured by X ray diffractometer.The results show that the microstructure was martensite with the lath width about 300~500 nm.The lath was clear and the precipitates were about 20 nm,finer than those by conventional process after treated by induction heating tempering process.The yield strength was improved by both processes.However,the total elongation is above 16% and-40 ℃ toughness was above 32 J for the steel treated by induction heating tempering at 500 ℃.The mechanical properties of steel is superior to that by traditional quenched and tempered process.Much more small size precipitates and retained austenite improved the plasticity and toughness of the steel,which were obtained by induction heating tempering.
展开▼
