冷却工艺对40CrMoNbVTi钢组织和性能的影响  

Effect of cooling process on microstructure and properties of 40CrMoNbVTi steel

作　　者：孙永真 程巨强[1] 李玫萱 Sun Yongzhen;Cheng Juqiang;Li Meixuan(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》2022年第12期74-77,共4页Heat Treatment of Metals

摘　　要：研究了冷却工艺对40CrMoNbVTi钢组织和性能的影响。结果表明,780℃淬火油冷、550℃回火后试样具有较高的抗拉强度和冲击吸收能量,分别为1250 MPa和78.63 J;20%聚乙二醇商用淬火液冷却后的抗拉强度为1140 MPa,冲击吸收能量为80.7 J;油冷及20%聚乙二醇淬火液冷却后组织为索氏体组织和少量的铁素体。860℃淬火雾冷/空冷+550℃回火后试样的抗拉强度分别为1010 MPa和945 MPa,冲击吸收能量分别为35.7 J及38.4 J,组织为回火索氏体或粒状贝氏体。780℃淬火油冷/商用淬火液冷却是较为合适的淬火冷却工艺。780℃淬火油冷/20%聚乙二醇淬火液冷却+550℃回火后冲击断裂机制为韧性断裂,860℃淬火雾冷/空冷550℃回火后冲击断裂机制为脆性断裂,增加淬火冷却速度可以改善冲击断口形貌。Effect of cooling process on microstructure and properties of 40CrMoNbVTi steel was studied.The results show that the specimens quenched at 780℃,oil cooled and tempered at 550℃have higher tensile strength and impact absorbed energy,which are 1250 MPa and 78.63 J,respectively.After cooling by 20%polyethylene glycol quenching solution,the tensile strength is 1140 MPa,and the impact absorbed energy is 80.7 J.The microstructure is sorbite and a small amount of ferrite after oil cooling and 20%polyethylene glycol quenching solution cooling.The tensile strength of the specimens quenched at 860℃,fog cooled/air cooled,and tempered at 550℃is 1010 MPa and 945 MPa respectively,the impact absorbed energy is 35.7 J and 38.4 J,respectively,and the microstructure is tempered sorbite or granular bainite.Quenching at 780℃,oil cooling/commercial quenching solution cooling are more suitable quenching cooling processes.The impact fracture mechanism of quenching at 780℃,oil cooling/20%polyethylene glycol quenching cooling,tempering at 550℃is ductile fracture,while the impact fracture mechanism of quenching at 860℃,fog cooling/air cooling,tempering at 550℃is brittle fracture.Increasing the quenching cooling rate can improve impact fracture morphology.

关 键 词：40CrMoNbVTi钢 冷却工艺 组织 性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]