摘要
试验ML20Cr钢280 mm×325 mn连铸坯的生产流程为80 t顶底复哄转炉-LF-CC工艺。借助Gleeble1500热模拟试验机测试了试验钢连铸坯的650~1 200℃热塑性曲线.许分析了添加0.029Ti-0.002 3B对ML20Cr钢(/%:0.21~0.22C.0.22~0.235i,0.74~0.76Mn,0.015~0.017P,0.002~0.003S,0.95~0.96Cr.0.034~0.036A1,0.005 0~0.005 1N)热塑性的影响。结果表明,在650~900℃范旧,含0.029Ti-0.002 3B的ML20Cr钢的塑性(750℃断面收缩率>70%)优于不加Ti-B的ML20Cr钢(750℃断面收缩率<50%)。其主要原因TiN优先析出,降低了细小AlN析出物在第三脆性区的影响,同时B元素在奥氏体晶界偏聚,抑制先共析铁素体薄膜的形成,从而有效改善了钢的热塑性、工业生产结果表明,加微量Ti-B后ML20Cr连铸坯开裂率由3.7%降低到0.3%、
The production flowsheet of tested 280 mm ×325 mm casting bloom of steel ML20Cr is 80 t top and bottom combined blowing converter-LF-CC process. The hot ductility curves of casting bloom of tested steel at 650 - 1 200 ℃ are measured by Gleeble 1500 hot simulator, and the effect of adding 0. 029Ti-0. 002 3 B on hot ductility of steel MLCr20 （/%： 0.21-0.22C, 0.22- 0. 23Si, 0.74- 0. 76Mn, 0.015- 0.017P, 0.002- 0.003S, 0.95- 0.96Cr, 0.034- 0. 036A1, 0. 005 0 -0. 005 1 N） is analyzed. Results show that in 650 -900 ℃ the plasticity of steel ML20Cr containing 0. 029Ti-0. 002 3B （reduction of area 〉 70% at 750 ℃ ） is better that of steel ML20Cr un-adding Ti-B （reduction of area 〈 50% at 750 ℃ ）. The main reason is that the prior precipitated TiN decreases the effect of fine A1N in Nom brittle zone, and the B segregate at austenite grain boundary to inhibit the formation of proeutectoid ferrite thin film, in order to effective- ly improve the hot ductility of steel. The commercial production results show that with adding micro Ti-B in steel ML20Cr the cracking rate of casting bloom decreases from 3.7% to 0. 3%.
出处
《特殊钢》
北大核心
2017年第2期53-55,共3页
Special Steel
