节镍型高氮奥氏体不锈钢固溶处理加热过程中的组织演变

对节镍型高氮奥氏体不锈钢进行固溶处理,通过控制加热温度和保温时间,研究高氮奥氏体不锈钢组织的变化规律。结果表明,800℃保温1 h后微观组织中出现混晶,在变形组织的晶界处产生细小的动态再结晶晶粒。在900～1050℃,随温度的升高,再结晶晶粒数量增多,尺寸增大。保温时间的增长会导致晶粒逐渐长大。在1200℃保温,晶粒尺寸从保温0. 5 h时的70μm增长到保温1 h时的117μm,此时晶粒最为均匀。平均晶粒尺寸随时间的变化呈抛物线增长,符合Beck方程:D=105.1t^0.45。并根据试验得到试验钢的最佳热处理方式为1050～1200℃保温1 h。 

Microstructure evolution of low nickel high nitrogen austenitic stainless steel during heating in solid solution treatment

Solution heat treatment of low-nickel high nitrogen austenitic stainless steel was carried out,and microstructure evolution of the steel was researched by controlling the temperature and the holding time. The results show that mixed grains are found at 800 ℃ for 1 h,fine dynamic recrystallization grains appear at the grain boundaries of the deformed microstructure. At 900-1050 ℃,with increase of the temperature,the number of recrystallized grains increases and the grain size increases. Holding at 1200 ℃,the average grain size increases from 70 μm at 0. 5 h after incubation to 117 μm at 1 h,whereupon the grains are the most uniform. The average grain size shows a parabolic growth law with time,in accordance with Beck equation: D-= 105. 1t^0. 45. According to the experiment,the best heat treatment for the steel is holding at 1050-1200 ℃ for 1 h.