【作者】 陈伟； 徐锟； 李龙飞； 杨王玥； 孙祖庆；

【Author】 Chen Wei;Xu Kun;Li Longfei;Yang Wangyue;Sun Zuqing;Baosteel Group Changzhou Roll Manufacture Company;State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing;School of Materials Science and Engineering, University of Science and Technology Beijing;

【机构】 宝钢集团常州轧辊制造公司； 北京科技大学新金属材料国家重点实验室； 北京科技大学材料科学与工程学院；

【摘要】 本文利用Gleeble 1500热模拟试验机进行单轴热压缩实验,并结合SEM、EBSD观察和力学性能测试,研究了过共析钢(T10)在Acm~Arcm和A1~Ac1温度范围内两阶段循环变形后缓冷所得超细化(α+θ)复相组织的转变过程及其力学行为。结果表明:过共析钢在Acm~Arcm温度范围内进行过冷奥氏体形变后,在A1~Ac1温度范围内再变形时,可以利用应变量控制再奥氏体化进程,在一定应变量下获得奥氏体与未溶渗碳体粒子的混合组织,在随后的缓冷过程中发生离异共析转变,获得超细化(α+θ)复相组织,其中α-Fe平均晶粒尺寸小于3μm,且以大角度晶界为主(约占94%),θ-Fe3C粒子平均尺寸小于0.4μm。力学性能测试表明该复相组织表现出优异的综合力学性能,在保持较高强度(屈服强度为641 MPa,抗拉强度为874 MPa)的同时具有良好的塑性,总延率接近20%,且具有较高的加工硬化能力。更多还原

【Abstract】 The mechanical properties and microstructure refinement of hypereutectoid steel based on Divorced Eutectoid Transformation(DET) were investigated by hot uniaxial compression tests on a Gleeble 1500 in combination with SEM, EBSD and mechanical test. The results indicate that during hot deformation in the temperature of A1 to Ac1 after hot deformation of under cooled austenite in the temperature rang of Acm to Arcm, the re-austenization could be controlled by the applied strain, leading to the formation of the mixing microstructure of austenite plus undissolved cementite particles at certain conditions. During subsequent slow cooling, DET took place, resulting in the formation of an ultrafine(α+θ) microduplex structure with α-Fe grains less than 3μm and the fraction of high angle boundaries in its ferrite matrix was higher than 90%, θ-Fe3 C particles less than 0.4μm. The microduplex structure obtained by cycle deformation demonstrated the best mechanical properties, with the high yield strength being 641 MPa and the high tensile strength being 874 MPa, the total elongation was close to 20%, and have a good work hardening ability.更多还原