杨庚蔚,雍岐龙,孙新军,李昭东,李晓闲

• 1:昆明理工大学材料科学与工程学院
• 2:钢铁研究总院工程用钢研究所

摘要(Abstract)：

通过低成本成分设计,在控制轧制的基础上,分别采用直接淬火(DQ)、直接淬火+回火(DQ+T)以及再加热淬火+回火(RQ+T)工艺成功制得了抗拉强度1500 MPa级经济型低合金高强高韧钢。对比研究了DQ、DQ+T和RQ+T 3种工艺钢的微观组织和力学性能。结果表明:DQ工艺钢的微观组织为板条马氏体+少量铁素体及残留奥氏体的复相组织,其抗拉强度和屈服强度分别为1750 MPa和1300 MPa,-40℃下冲击吸收功为37 J。200℃回火1 h后,试验钢位错密度降低,大量细小ε碳化物在板条内析出。DQ+T工艺钢屈服强度达到1400 MPa,-40℃下冲击功为43 J。试验钢直接淬火后再加热至880℃,获得了平均晶粒尺寸为5.7μm的细小等轴奥氏体。相比于DQ及DQ+T工艺钢,RQ+T工艺钢获得了更高的韧性,冲击功达到56 J。研究发现,未溶的(Nb,Ti)(C,N)粒子能有效抑制奥氏体晶粒长大。组织细化及残留奥氏体是RQ+T工艺钢获得高韧性最主要的原因。

关键词(KeyWords)： 低合金高强高韧钢;直接淬火;扁平奥氏体;板条马氏体;强韧化机理

Abstract:

Keywords:

基金项目(Foundation): 国家重点基础研究发展计划(2010CB630805)

作者(Author): 杨庚蔚,雍岐龙,孙新军,李昭东,李晓闲

DOI: 10.13289/j.issn.1009-6264.2013.07.024

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