退火工艺对δ铁素体在301L不锈钢铸坯中溶解行为的影响  

Effect of Annealing Process on Dissolution Behavior ofδFerrite in 301L Stainless Steel Casting Billet

作　　者：李俊琛[1] 王东 LI Junchen;WANG Dong(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050

出　　处：《热加工工艺》2024年第16期49-52,共4页Hot Working Technology

基　　金：甘肃省科技计划(创新基地和人才计划)项目(17JR5RA131);甘肃省科技计划(科技重大专项)项目(17ZD2GB012)。

摘　　要：利用高温热处理炉,分析了轧制前热处理对301L不锈钢铸坯的溶解行为。结果表明,退火时间和温度对δ铁素体在301L铸坯中的溶解影响显著,溶解初期,δ铁素体的含量从12wt%降至6wt%以下。随着退火时间的延长和温度的升高,301L铸坯固态中δ铁素体含量减少,受Cr、Ni的扩散控制显著,1300℃扩散退火60 min后铁素体球化,晶粒尺寸减小为2~3μm,节点处平衡态δ铁素体的球化行为降低了γ/α界面的附加应力,有利于轧制过程。利用动力学方程验证了后期Cr、Ni元素对组织的影响,当退火温度为1210℃时,溶解参数K_(Ni)^(γ)为0.26,Ni的扩散系数D_(NiNi)^(γ)=4.8×10-10cm2/s。δ铁素体的体积分数与退火时间t1/2成正比。研究结果可为301L铸坯的组织控制提供理论指导。The dissolution behavior of 301L stainless steel casting billet by heat treatment furnace before rolling was analyzed.The results show that the dissolution ofδferrite in 301L billet is significantly affected by annealing time and temperature.At the beginning of dissolution,the content ofδferrite decreases from 12wt%to less than 6wt%.With the increase of annealing time and temperature,the decrease ofδferrite content in the solid state of 301L billet is significantly controlled by the diffusion of Cr and Ni.After diffusion annealing at 1300℃for 60 min,ferrite spheroidized and the grain size decreases to 2-3μm.The spheroidization behavior of the equilibriumδferrite at the node reduces the additional stress at theγ/αinterface and facilitates the rolling process.The effects of Cr and Ni on the microstructure are verified by the kinetic equation.When the annealing temperature is 1210℃,the dissolution parameter K_(Ni)^(γ) is 0.26,and the diffusion coefficient of Ni is D_(NiNi)^(γ)=4.8×10-10 cm2/s.The volume fraction ofδferrite is proportional to the annealing time t1/2.The research results can provide theoretical guidance for the microstructure control of 301L casting billet.

关 键 词：301L铸坯 退火 Δ铁素体 扩散溶解 

分 类 号：TG161[金属学及工艺—热处理]