碳化物形貌对高强钢回火残余应力的影响  

Influence of carbide morphology on residual stress of high strength steel during tempering

作　　者：吴挺 丁文红 祁聪 孙力 刘天武 潘进 张志强 WU Ting;DING Wen-hong;QI Cong;SUN Li;LIU Tian-wu;PAN Jin;ZHANG Zhi-qiang(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;HBIS Group Technology Research Institute,Shijiazhuang 050023,China;Technology Center,HBIS Group Hansteel Company,Handan 056002,China)

机构地区：[1]武汉科技大学耐火材料与冶金国家重点试验室,湖北武汉430081 [2]河钢集团钢研总院,河北石家庄050023 [3]河钢集团邯钢公司技术中心,河北邯郸056002

出　　处：《材料热处理学报》2021年第2期80-88,共9页Transactions of Materials and Heat Treatment

基　　金：湖北省技术创新专项重大项目(2018AA005)。

摘　　要：研究了不同升温速率回火条件下,碳化物尺寸及形貌对高强钢残余应力的影响。结果表明:300℃低温阶段,合金渗碳体析出使残余应力所产生的弹性应变转化为析出塑性应变,是试验钢残余应力得以消减的关键因素。析出塑形应变的大小与析出碳化物的尺寸、形貌密切相关。碳化物的尺寸越细小、分布越弥散,产生的析出塑性越大。升温速率是影响碳化物形貌及分布的重要因素,高升温速率有助于基体保持较高密度的位错,诱导碳化物在晶内弥散析出,增加碳化物析出过程中的残余应力调控能力。500~650℃高温阶段,合金碳化物的析出主导材料的析出塑性行为。由于合金碳化物的尺寸更小,分布更为弥散,因此,高温阶段合金碳化物的析出对残余应力的调控能力更为显著。Influence of carbide size and morphology on residual stress of high strength steel under different tempering conditions with different heating rates was studied. The results show that at the tempering temperature of 300 ℃, the precipitation of cementite makes the elastic strain produced by residual stress transformed into precipitation plastic strain, which is the key factor for the reduction of the residual stress of the experimental steel. The magnitude of the precipitation plastic strain is closely related to the size and morphology of the precipitated carbides. The smaller the size and the more dispersed the distribution of the carbides, the greater the precipitation plasticity. The heating rate is an important factor affecting the morphology and distribution of the carbides. The high heating rate can help the matrix to maintain a high density of dislocations, induce the dispersion and precipitation of the carbides in the grain, and increase the ability of alloy carbide precipitation to control the residual stress. At the high tempering temperature of 500-650 ℃, the precipitation of alloy carbides dominates the precipitation plastic behavior of the experimental steel. Because the size of the alloy carbides is smaller and the distribution is more dispersed, the ability of alloy carbide precipitation to control residual stress is more significant in high temperature stage.

关 键 词：升温速率 残余应力 碳化物析出 相变塑性 

分 类 号：TG142.3[一般工业技术—材料科学与工程]