冷却工艺对贝氏体钢拉杆组织和性能的影响  

Effect of heat treatment and cooling process on microstructure and properties of bainitic steel tie-rods

作　　者：李梦鸽 程巨强[1] 尹思博 Li Mengge;Cheng Juqiang;Yin Sibo(College of Materials Science and Chemical Engineering,Xi'an Technological University,Xi'an Shaanxi 710021,China)

机构地区：[1]西安工业大学材料与化工学院,陕西西安710021

出　　处：《金属热处理》2021年第7期178-182,共5页Heat Treatment of Metals

摘　　要：研究了热处理冷却工艺对贝氏体钢拉杆组织及力学性能的影响。试验结果表明,φ70 mm贝氏体钢拉杆材料经920℃空冷+300℃回火、920℃水冷30 s后出水空冷+300℃回火后,杆体的组织为贝氏体铁素体和残留奥氏体;经920℃水冷+200℃回火后,杆体的组织为回火板条马氏体和残留奥氏体。920℃水冷+200℃回火时棒料1/2半径处的R_(m)为1513 MPa、KV_(2)为73.2 J、硬度为46.5 HRC;920℃水冷30 s后空冷+300℃回火时棒料1/2半径处的R_(m)为1254 MPa、KV_(2)为76.0 J、硬度为42.0 HRC;920℃空冷+300℃回火时棒料1/2半径处的R_(m)为1226 MPa、KV_(2)为75.5 J、硬度为41.9 HRC。φ70 mm贝氏体钢拉杆热处理先水冷后空冷可以提高其冲击性能。The effects of heat treatment and cooling process on the microstructure and mechanical properties of the bainitic steel tie-rod with 70 mm in diameter were studied.The results show that the structure of the rod is bainite ferrite and residual austenite when heated at 920℃and air cooled,and then tempered at 300℃,or heated at 920℃,water cooled for 30 s and air cooled,and then tempered at 300℃.The structure of the rod body is tempered lath martensite and retained austenite when heated at 920℃,water cooled and then tempered at 200℃.At half radius of the bar after water cooling at 920℃and tempering at 200℃,R_(m) is 1513 MPa,KV_(2) is 73.2 J,hardness is 46.5 HRC;after water-cooling for 30 s and air cooling at 920℃and tempering at 300℃,R_(m) is 1254 MPa,KV_(2) is 76.0 J,hardness is 42.0 HRC;after air cooling at 920℃and tempering at 300℃,R_(m) is 1226 MPa,KV_(2) is 75.5 J and hardness is 41.9 HRC.When the φ70 mm bainitic steel tie rod is actually normalized,the impact toughness can be improved by water-cooling before air-cooling.

关 键 词：冷却方式 贝氏体钢拉杆 组织 性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]