带状组织对铁素体-马氏体钢拉伸断裂行为的影响  

Effect of Banded Structure on Tensile Fracture Behavior of Ferritic-Martensitic Steel

作　　者：李琳[1,3] 徐锐良 李忠利 胡亚楠 LI Lin;XU Ruiliang;LI Zhongli;HU Yanan(Hebi Vocational and Technical College,Hebi 458030,China;School of Vehicle and Traffic Engineering,Henan University of Science and Technology,Luoyang 471000,China;Henan Jiyuan Iron&Steel Co.,Ltd.,Jiyuan 454650,China)

机构地区：[1]鹤壁职业技术学院,河南鹤壁458030 [2]河南科技大学车辆与交通工程学院,河南洛阳471000 [3]河南济源钢铁有限公司,河南济源454650

出　　处：《热加工工艺》2021年第14期46-50,共5页Hot Working Technology

基　　金：国家重点研发计划项目(2017YFB0304800);中央高校基本科研业务费专项资金资助项目(300102318206)。

摘　　要：利用单轴拉伸仪、金相光学显微镜(OM)、扫描电子显微镜(SEM)等研究对比了两种不同马氏体形态的铁素体-马氏体双相钢的拉伸性能及拉伸过程中的显微组织。结果表明:不均匀的带状组织对双相钢的各向均匀性具有显著影响,抗拉强度在轧向和纵向上相差约29 MPa,且相对于均匀马氏体具有更差的塑性。中心厚度处存在马氏体带试样的断口形态表现出与马氏体相关的非常大而深的凹坑,而马氏体均匀试样的断口具有典型的韧性断裂特性,这主要是由于马氏体分布影响了双相钢的断裂机理。含马氏体带试样中空隙的形核最初在马氏体的局部开裂(局部应变0.03),然后由铁素体-马氏体解理开始空隙形核(局部应变0.10),并且在相邻的马氏体区域分离而发生;而马氏体分布均匀的试样主要的空隙形核机制是在铁素体-马氏体界面处的解理(局部应变1.50),且沿着铁素体晶粒边界生长,在开裂的马氏体颗粒上形核的空隙较少。The tensile fracture behavior and microstructure in tensile process of ferrite-martensitic dual phase steels in two different martensile states were studied by uniaxial tensile tester,OM and SEM.The results show that the banded structure has an effect on the isotropic homogeneity of the dual phase steel.The difference of tensile strength in rolling direction and longitudinal direction is about 29 MPa,and the plasticity is worse than that of martensite with uniform distribution.The fracture morphology of the specimen with martensite zone at the center thickness shows a very large and deep pit related to martensite,while the fracture of the specimen with uniform martensite distribution has typical ductile fracture characteristics,which is mainly due to the influence of martensite distribution on the fracture mechanism of dual phase steel.The nucleation of voids in the specimen with martensitic band begins with local cracking of martensite(local strain 0.03),and then begins with ferrite martensite cleavage(local strain 0.10),and occurs due to the separation of adjacent martensite regions.However,the main void nucleation mechanism of the specimen with uniform martensite distribution is cleavage(local strain 1.50)at the ferrite-martensite interface,and which grows along the ferrite grain boundary,and there are few voids on the cracked martensite particles.

关 键 词：铁素体-马氏体 带状组织 碳含量 拉伸断裂行为 

分 类 号：TG142.1[一般工业技术—材料科学与工程]