热处理工艺对NM450耐磨钢组织与性能的影响

Influence of Heat Treatment Process on the Microstructure and Property of Wear-resistant Steel NM450

对控轧控冷工艺生产的16 mm厚度规格NM450耐磨钢板进行930℃+保温20 min淬火、200℃+保温25 min回火处理,并对热轧态、淬火态及回火态的钢板取样进行组织性能分析。结果表明,热轧后钢板组织为铁素体+珠光体以及少量贝氏体,淬火组织为马氏体+残余奥氏体以及少量贝氏体,回火组织为马氏体+残余奥氏体+针状贝氏体。试验钢淬火+回火处理后Rm1 378 MPa,A5021.5%,-20℃夏比冲击功61 J,表面布氏硬度443 HBW,具有良好的综合力学性能。

The heat treatment process quenching at 930 ℃ ＋ holding for 20 mins and tempering at 200 ℃＋ holding for 25 mins were carried out for 16 mm NM450 wear-resistant steel plate produced by controlled rolling and controlled cooling process. The microstructure and properties of as-rolled, quenched, and tempered steel plates were sampled and analyzed. The results showed that, there were ferrite ＋ pearlite and a little of bainite in the microstructure of as-rolled plate, martensite ＋ retained austenite and a small amount of bainite in the microstructure of quenched plate, and martensite ＋ retained austenite ＋ acicular bainite in the microstructure of tempered plate. After the tested steel was quenched and tempered, its tensile strength was 1 378 MPa, its elongation A50 was 21.5%, its charpy impact energy at -20 ℃ was 61 J, its brinell hardness on plate surface was 443 HBW. The steel plate possesses a good comprehensive mechanical property.