加热温度对高强钢高温热态气体成形的影响  

Effect of Heating Temperature on High Temperature Hot Gas Forming of High Strength Steel

作　　者：刘发[1] 刘洪伟[1] 赵洪运[1] 吴来军 LIU Fa;LIU Hongwei;ZHAO Hongyun;WU Laijun(School of Materials Science and Engineering,Harbin Institute of Technology at Weihai,Weihai 264209,China)

机构地区：[1]哈尔滨工业大学(威海)材料科学与工程学院,山东威海264209

出　　处：《热加工工艺》2020年第21期19-22,共4页Hot Working Technology

摘　　要：通过初始加热温度的变化,研究了高强钢管扭力梁高温热态气压成形后的力学性能、组织、硬度的变化规律。实验结果表明,随着初始加热温度的升高,在扭力梁冷却速率较快的区域,马氏体含量逐渐增加,成形后抗拉强度、升高,伸长率下降,但初始加热温度超过930℃,马氏体转化量降低且晶粒变大,抗拉强度开始下降;在扭力梁两端部位即冷却速率较慢区域,成形后主要是铁素体和珠光体混合组织,随着初始加热温度的升高,抗拉强度在630 MPa上下5%范围内波动,伸长率在14.5%~16.5%范围内波动。零件各部位硬度值随着初始加热温度升高而增大。在15 MPa固定气体压力和成形温度930℃时,成形件尺寸形状精度良好。The mechanical properties, microstructure and hardness of high strength steel pipe after hot gas pressure forming were studied by the change of initial heating temperature. The experimental results show that with the increase of initial heating temperature, the martensite content increases gradually in the fast cooling part of the torsional beam, the tensile strength increases and the extension decreases after forming;when the temperature is more than 930 ℃, the content of martensite decreases, the grain becomes larger, the tensile strength begins to decrease. In the region at both ends of the torsional beam where the cooling rate is slow, the mixed microstructure of ferrite and pearlite is mainly formed, and with the increase of the initial heating temperature, the tensile strength fluctuates in the range of 630 MPa above and below 5%, the elongation fluctuates in the range of 14.5% and 16.5%. The hardness of each part of the part increases with the increase of the initial heating temperature. When the fixed gas pressure is 15 MPa and the forming temperature is 930 ℃, the size and shape accuracy of the forming part is good.

关 键 词：高强钢 气压成形 马氏体 

分 类 号：TG306[金属学及工艺—金属压力加工]