奥氏体晶粒对52CrMoV4弹簧钢强韧性的影响  

Effect of austenite grain size on strength and toughness of a spring steel 52CrMoV4

作　　者：徐平伟[1,2] 梁益龙[1,2] 黄朝文[1,2] 

机构地区：[1]贵州大学材料与冶金学院,贵州贵阳550003 [2]贵州省材料结构与强度重点实验室,贵州贵阳550003

出　　处：《材料热处理学报》2012年第1期89-93,共5页Transactions of Materials and Heat Treatment

基　　金：国家科技支撑计划(2007BAE11B03);黔科合重大专项字(2006)6029

摘　　要：采用850℃至1200℃的淬火温度,探索了奥氏体晶粒尺寸对52CrMoV4弹簧钢强韧性的影响。通过光学金相和扫描电镜观察了显微组织和断口形貌及断裂路径。结果表明,随着晶粒的粗化,强度变化很小,拉伸塑性呈线性降低,断裂韧度和冲击韧度呈现先降后增的反常趋势。晶粒尺寸和马氏体束尺寸是影响拉伸塑性的重要因素,而断裂韧度和冲击韧度与晶界状况和马氏体条的宽长比有关。Effect of austenite grain size on strength and toughness of 52CrMoV4 spring steel after quenching from 850 ℃ to 1200 ℃ was studied. Microstructure, fractography, and fracture path of the steel were invesgated by optical metallography and scanning electron microscopy（SEM）. The results show that strength of the steel varies slightly, tensile ductility linearly decreases, while both fracture toughness and impact toughness abnormally decrease and then increase when the prior austenite grain gets coarsened from 10 tLm to 200 um. Grain size and martensite packet size are the crucial factors of tension ductility, while both fracture toughness and impact toughness are related to grain boundary condition and aspect ratio of martensite lath.

关 键 词：奥氏体晶粒 马氏体 断裂韧度 强韧性 弹簧钢 

分 类 号：TG142.41[一般工业技术—材料科学与工程]