超快冷工艺下工程机械用550MPa级钢的组织与性能

摘要

A kind of 550 MPa steel used for engineering machinery with low cost was prepared,and the effects of ultra fast cooling process after rolling on microstructure and mechanical property of the steel were studied.The results show that the ultra fast cooling process could increase the properties of the steel effectively,and the yield strength,tensile strength,elongation and impact energy at-20 ℃ were 600 MPa,755 MPa,19% and 253 J,respectively.The microstructure of the steel after ultra fast cooling was bainite,and the reinforcement phases were fine bainite and fine precipitation distributing in matrix.%制备了低成本工程机械用550MPa级钢,研究了轧后超快冷工艺对该钢组织与性能的影响。结果表明：超快冷工艺有效提高了该钢的力学性能,其屈服强度、抗拉强度和断后伸长率分别可达600MPa,755MPa,19%,-20℃的冲击功为253J;超快冷后钢的组织为贝氏体,其强化相为细小的贝氏体及基体中分布着的细小析出相。