100t EAF-LF-VD-CC流程冶炼非调质钢49MnVS3的工艺实践

摘要

10炉非调质钢49MnVS3(/％:0.46 ～ 0.48C,0.30 ～ 0.40Si,0.88～0.92Mn,0.001 ～0.014P,0.004～0.005S,0.09 ～0.10V,0.19 ～0.22Cr)由100 t EBT DC EAF-LF-VD-260 mm×340 mm坯连铸-Φ140～150 mm材轧制流程生产.采用兑入75％铁水,EAF前期脱磷至≤0.015％P,出钢前[C]为0.20％ ～0.30％,精炼时加150 ～ 200kg碳化硅,控制LF精炼渣碱度2.80 ～2.95,(CaO)/(Al2O3)=1.2 ～ 1.6,VD后喂1.5 m/t钙铁线,软吹时间≥15min等工艺措施,49MnVS3钢中[N]、[H]和[O]分别为130×10-6 ～ 220×10-6,1.2×10-6～1.5 × 10-6和5×10-6～11×10-6,成品材晶粒度≥5级,非金属夹杂物和低倍组织均≤1.5级,组织(带状≤1级)和力学性能(Rm803 ～883 Mpa,Rel517 ～590 Mpa,A 16％ ～21％,AKU 39 ～99 J)均满足标准要求.