(1. 燕山大学 先进锻压成型技术与科学教育部重点实验室,秦皇岛 066004;
2. 燕山大学 河北省并联机器人与机电系统实验室,秦皇岛 066004;
3. 燕山大学 机械工程学院,秦皇岛 066004)
摘 要: 依据不锈钢复合板双层金属特性,制定真空热轧成形316L/Q345R复合板热处理工艺为高温快速冷却+低温缓慢冷却。采用电子显微与能谱图分析分别对热处理前、后复合板试样进行显微组织特征观察和成分含量测定,研究复合界面显微组织、相结构和成分变化规律。采用剪切、拉伸及冲击功试验对两种状态试样进行力学性能测试,研究显微组织对力学性能的影响规律。结果表明:真空热轧后的复合板能较好复合,热轧试样中低合金钢侧组织为铁素体和珠光体,力学性能较差,不锈钢侧析出Cr的碳化物较多;经过热处理后,试样组织中有贝氏体出现,不锈钢侧Cr在加热制度下重新固溶。热处理实现复相化组织、合金元素界面扩散等复合组织结构的协同作用,从而大幅改善复合板的力学性能和耐腐蚀性能。
关键字: 不锈钢复合板;真空热轧成形;热处理;显微组织;力学性能
(1. Key Laboratory of Advanced Forging and Stamping Technology and Science, Ministry of Education,
Yanshan University, Qinhuangdao 066004, China;
2. Hebei Province Key Laboratory of Parallel Robot and Mechatronic System, Yanshan University,
Qinhuangdao 066004, China;
3. School of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China)
Abstract:According to the double layer metal characteristics of stainless steel clad plate, the heat treatment process, high temperature and rapid cooling and low temperature and slow cooling, for 316L/Q345R clad plate after vacuum hot rolling was formulated. Scanning electron microscope and energy spectrum analysis were used to investigate the microstructure, topography and constituent of clad plate specimens before and after heat treatment. The change rules of interface microstructure, phase structure and constituent were also studied. By applying shear, stretch and impact tests, the mechanical properties of specimens at two states were tested to investigate the relationship between the microstructure and mechanical properties. The results indicate that, after vacuum hot rolling, the clad plate can be successfully combined. The low alloy steel side microstructure of hot rolling sample consists of ferrite and pearlite, so, the mechanical property is poor. The precipitation of Cr carbide is more in the stainless steel side. After heat treatment, Bainite appears in the microstructure of sample, and Cr of the stainless steel side is dissolved again in the heating system. The heat treatment can achieve the synergistic effect of composite structures, such as duplex structure and interfacial diffusion of alloy elements, thus, greatly improve the mechanical properties and corrosion resistance of clad plates.
Key words: stainless steel clad plate; vacuum hot rolling; heat treatment; microstructure; mechanical property