高碳奥氏体不锈钢流变行为预测及热加工性研究  

Prediction of flow behavior and study on hot workability of high carbon austenitic stainless steel

作　　者：黄健 庞宗旭 张建平 王勇 赵宝纯 王铁 HUANG Jian;PANG Zong-xu;ZHANG Jian-ping;WANG Yong;ZHAO Bao-chun;WANG Tie(State Key Laboratory of Metallic Materials for Marine Equipment and Applications,Anshan 114009,China;Iron&Steel Research Institutes of Ansteel Group Corporation,Anshan 114009,China)

机构地区：[1]海洋装备金属材料及其应用全国重点实验室,辽宁鞍山114009 [2]鞍钢集团钢铁研究院,辽宁鞍山114009

出　　处：《塑性工程学报》2025年第4期181-190,共10页Journal of Plasticity Engineering

摘　　要：为了使高碳奥氏体不锈钢轧制后晶粒分布均匀,采用Gleeble-3800热力模拟试验机在变形温度范围为900~1200℃、应变速率范围为0.01~10 s^(-1)、真应变为0.69条件下进行压缩试验。根据真应力-真应变曲线得到高温变形时的软化机制,通过Johnson-Cook(JC)模型实现流变应力的精确预测,并根据动态材料模型理论建立了该钢的热加工图,得到最佳的热加工工艺窗口。结果表明,在变形温度低于1050℃时,动态回复与动态再结晶共同控制材料的软化,变形温度高于1050℃时材料的软化由动态再结晶主导。基于修正JC模型构建了316H不锈钢本构模型,预测值的平均绝对相对误差eAARE为6.1%,相关系数R为0.977,该模型具有较高的精度。基于不同真应变建立的热加工图表明,材料的失稳区位于高温高应变速率和低温全应变速率区域,且随着应变量的增加,低温失稳区面积减小。大应变(0.69)下的最佳热加工区域对应于温度范围为1057~1200℃,应变速率范围为0.01~2 s^(-1),在1100℃-0.01 s^(-1)时的峰值效率为0.422。在该区域中,原来锻后的粗大晶粒可以被均匀细小再结晶粒取代,说明动态再结晶造成了高的功率耗散值。In order to obtain uniformly distributed grains of high carbon austenitic stainless steel after rolling,the compression experiments were performed by using Gleeble-3800 thermal mechanical simulator at temperatures of 900-1200℃,strain rates of 0.01-10 s^(-1),and true strain of 0.69.According to the true stress-true strain curves,the softening mechanism during high-temperature deformation was obtained,the flow stress was accurately predicted by Johnson-Cook(JC)model.The hot processing maps of the steel were established based on the dynamic material model theory,and the optimal hot processing process window was obtained.The results show that when the deformation temperature is below 1050℃,the softening of the material is controlled by both dynamic recovery and dynamic recrystallization.When the deformation temperature is higher than 1050℃,the softening of the material is dominated by dynamic recrystallization.A constitutive model for 316H stainless steel was constructed based on the modified JC model.The average absolute relative error eAARE of the predicted values is 6.1%,and the correlation coefficient R is 0.977,indicating that the model has high accuracy.The hot processing maps established based on different true strains indicate that the instability areas of the material are located in the high-temperature,high strain rate and low-temperature,full strain rate areas,and the area of the low-temperature instability area decreases with the increase of strain.The optimal hot processing area under high strain(0.69)corresponds to temperature of 1057-1200℃,strain rate of 0.01-2 s^(-1),and peak efficiency of 0.422 at 1100℃-0.01 s^(-1).In this area,the original coarse grains after forging can be replaced by uniformly fine recrystallized grains,indicating that dynamic recrystallization results in high power dissipation values.

关 键 词：奥氏体不锈钢 热变形 Johnson-Cook本构模型 热加工图 组织演变 

分 类 号：TG306[金属学及工艺—金属压力加工]