特殊钢 ›› 2017, Vol. 38 ›› Issue (6): 11-15.
赵斌1,崔怀周1,汪成义1,吴巍1,王欣2
Zhao Bin1, Cui Huaizhou1, Wang Chengyi1, Wu Wei1, Wang Xin2
摘要: 试验用Q420C钢(/%:0.18C,0.34Si,1.40Mn,0.013P,0.011S,0.066V,0.018Als,0.0110N)铸坯的冶炼工艺为80t BOF-LF-CC。采用Gleeble-1500D热模拟试验机测试Q420C钢连铸坯的600~1400℃热塑性,并利用金相显微镜、扫描电镜以及透射电子显微镜分析断口形貌及金相组织和研究凝固偏析和析出物粒子对铸坯热塑性的影响。结果表明,Q420C钢第Ⅰ脆性区为>1250~1350℃;第Ⅲ脆性区为700~1050℃;在1050~1250℃,断面收缩率大于60%。工业试验结果表明,通过控制Als含量0.015%~0.020%,适当降低二冷比水量(足辊段7~8t/h,Ⅰ段5.56.5t/h,托辊段14±1t/h), 铸坯矫直温度≥1050℃,轧材开裂率由原45.3%降至4.6%。