基于临界空穴扩张比理论的不锈钢管高温韧性损伤研究  

Study on high temperature ductile fracture of stainless steel tube based on critical void expansion ratio theory

作　　者：刘丰[1] 陈成成 陈凡海 吉鹏亮 韩毅[1] 徐东[3] LIU Feng;CHEN Cheng-cheng;CHEN Fan-hai;JI Peng-liang;HAN Yi;XU Dong(National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,Yanshan University,Qinhuangdao 066004,China;School of Mechanical Engineering,University of Science and Technology Beijing,Beijing 100083,China;Technology Innovation Center for High Quality Cold Heading Steel of Hebei Province,Hebei University of Engineering,Handan 056038,China)

机构地区：[1]燕山大学、国家冷轧板带装备及工艺工程技术研究中心,河北秦皇岛066004 [2]北京科技大学机械工程学院,北京100083 [3]河北工程大学、河北省高品质冷镦钢技术创新中心,河北邯郸056038

出　　处：《塑性工程学报》2023年第4期146-154,共9页Journal of Plasticity Engineering

基　　金：河北省自然科学基金资助项目(E2021203039,E2022203130)。

摘　　要：针对不锈钢管在高温塑性加工过程中出现的裂纹缺陷,在Gleeble-3800热模拟试验机上对TP321奥氏体不锈钢光滑棒材进行高温拉断试验,得到了TP321在温度850~1180℃、应变速率0.01~10 s^(-1)下的真应力-真应变曲线和试样拉伸断裂瞬间的等效塑性应变。结合有限元仿真,对试验结果进行了数值模拟,得到了应力三轴度的数值,从而计算出了临界空穴扩张比参数V GC。在此基础上,验证了临界空穴扩张比参数韧性断裂准则在高温下的适用性。发现在特定温度范围内TP321断裂瞬间的V GC与应变速率相关性较小,与温度呈线性关系,并建立了奥氏体不锈钢断裂瞬间的V GC与温度的数学表达式。将得到的V GC准则应用于TP321管坯的不同辊形斜轧穿孔过程中的韧性损伤,对比分析了不同辊形斜轧穿孔仿真结果,发现V GC准则可准确预测缺陷情况。Aiming at the crack defects of stainless steel tubes in the process of high temperature plastic processing,the high temperature tensile test of TP321 austenitic stainless steel smooth bar was carried out on Gleeble-3800 thermal simulator.The true stress-true strain curves and the equivalent plastic strain at the tensile fracture instant of TP321 were obtained at 850-1180℃and strain rate of 0.01-10 s^(-1).Combined with finite element simulation,the test results were numerically simulated to obtain the values of stress triaxiality and the critical void expansion ratio parameter V GC was calculated.Based on this,the applicability of the critical void expansion ratio parameter ductile fracture criterion at high temperatures was verified.It is found that the V GC at the fracture instant of TP321 in a specific temperature range has little correlation with the strain rate and a linear relationship with temperature.The mathematical expression for V GC versus temperature at the fracture instant of austenitic stainless steel was established.The obtained V GC criterion was applied to the ductility damage of TP321 pipe billets during the crossing roll piercing process with different roll shapes,and the simulation results of crossing roll piercing with different roll shapes were compared and analyzed,and it is found that the V GC criterion can accurately predict the defect condition.

关 键 词：钢管 斜轧穿孔 韧性损伤 临界空穴扩张比 应变速率 

分 类 号：TG335.71[金属学及工艺—金属压力加工] TG142.25[一般工业技术—材料科学与工程]