316L超低碳奥氏体不锈钢吹氮合金化的动力学研究和应用

Study on Metallurgical Kinetics of Blowing Nitrogen Alloying of Ultra-Low Carbon Austenite Stainless Steel 316L and Application

根据双膜理论,建立了不锈钢精炼中向钢水吹氮气合金化过程的动力学模型。通过硅钼棒炉研究了恒压(101 kPa),恒温(1 833 K)和恒流量(0.3 L/min)时316L不锈钢(/%:0.031C,0.57Si,1.00Mn,0.021P,0.004S,16.13Cr,10.12N,2.12Mo,0.028N)吹氮时间(0~70 min),氮分压(N_2:Ar=2:1,1:2和1:1)和温度(1 773~1 833K)对该钢氮合金化的影响。结果表明,钢中氮含量随着吹氮时间、氮分压的增加而增加,随吹氮流量增加钢液氮含量达到饱和的时间缩短,氮的溶解度随着钢液温度的降低而升高,合适的钢水温度为~1 500℃。120 t VOD 316L不锈钢工业生产试验表明,在氮气流量42×3 m^3/h时,VOD真空阶段吹氮合金化,钢中的氮含量可达0.04%。

According to double film theory the kinetics model of blowing nitrogen alloying in steel liquid during stain- less steel refining is established. By using silicon-molybdenum bar furnace the effect of nitrogen blowing time （0 - 70 min）, nitrogen partial pressure （N2： Ar =2： 1, 1：2 and 1 ： 1 ） and temperature （1 773 - 1 833 K） with constant pres- sure （ 101 kPa）, constant temperature 1 833 K and constant flow rate 0. 3 L/min on nitrogen alloying of stainless steel 316L （/% ： 0. 031C, 0. 57Si, 1.00Mn, 0. 021P, 0. 004S, 16. 13Cr, 10. 12N, 2. 12Mo, 0. 028N） has been studied. Results show that with increasing nitrogen blowing time and nitrogen partial pressure the nitrogen content in steel increases; with in- creasing nitrogen flow rate the blowing time for nitrogen content in liquid up to saturating value decreases; with decreasing liquid temperature the dissolvability of nitrogen in steel increases, and the suitable temperature of liquid is -1 500 ℃. The 120 t VOD commercial pilot production of stainless steel 316L show that by blowing nitrogen alloying during VOD vacuum period with nitrogen flow rate 42 x 3 m3/h the nitrogen content in steel may be up to 0. 04%.