【摘要】 研究1.37%C(质量分数)超高碳钢(UHCS-1.37C)经990℃奥氏体化,270℃和310℃等温淬火不同时间后空冷的组织和力学性能。组织研究表明,UHCS-1.37C经等温淬火热处理后获得了由纳米级贝氏体铁素体+薄膜状残余奥氏体组成的超级贝氏体组织。在同一等温温度下,随着等温时间的延长,超级贝氏体的数量不断增加,马氏体数量减少;在相同的等温时间内,等温温度越高,生成的超级贝氏体数量越多。力学测试结果表明,UHCS-1.37C在310℃等温8 h后获得了最佳的强韧性配合,其抗拉强度为1 622 MPa,断后伸长率为5.5%,冲击吸收能量为12.7 J。UHCS-1.37C等温组织优异的力学性能归因于超级贝氏体组织。更多还原

【Abstract】 The microstructures and mechanical properties of an ultrahigh-carbon steel with 1.37 wt.%C subjected to austenitization at single γ phase region and austempering at low temperatures have been studied. The results show that a superbainite comprising lamar bainite ferrite and film-type retained austenite is generated. An impact absorbed energy of 12.7 J,a fraction strength of 1 622 MPa and an elongation of 5.5% are obtained for UHCS-1.37 C austempered at 310℃ for 8 h. The combination of excellent strength and toughness is attributed to the superbainite.更多还原