40MnB合金钢硼含量的控制

莱钢特钢厂用50 t电弧炉-LF(VD)工艺生产40MnB钢。结果表明,通过保持LF精炼渣的渣碱度3.0～5.5,喂Al线,并在LF精炼末期喂硅钙线,扒渣后50 Pa VD处理35～40 min,VD后喂Al线,再喂钛线,用铝皮包裹FeB₂₀C_0.5-A硼铁插入钢水中,软吹氩,硼铁中硼的回收率为65%～75%,钢中硼含量为0.001 8%～0.002 5%,钢中氧含量≤20×10^-6,氮含量≤80×10^-6。

Control of Boron Content in Alloy Steel 40MnB

The steel 40MnB is produced by 50t EAF-LF(VD) process at Special Steel Plant,Laiwu Steel.Results showed that with insuring refining slag basicity 3.0～5.5,feeding Al wire,then feeding silicon-calcium wire in LF refining end phase,skimming and 50 Pa VD treated for 35~40 min,after VD feeding Al wire and titanium wire,and inserting ferroboron FeB₂₀C_0.5-A cladding of aluminium sheet into liquid steel and soft argon blowing,the yield of boron of ferroboron was 65%~75%,boron content in steel was 0.0018%～0.0025%,and oxygen content and nitrogen content in steel were respectively ≤20×10^-6 and ≤80×10^-6.