材料期刊网

对采用“EBT→LF→VD”工艺路线生产50Cr5MoV锻钢轧辊炼钢过程的全氧质量分数和夹杂物类型与数量进行了分析。结果表明：LF精炼后钢液中w(T[O])平均为0.0047%，VD出站w(T[O])为0.0014%，中间包w(T[O])为0.00155%，铸坯w(T[O])为0.0018%，轧材中w(T[O])降低至0.0010%。LF精炼初期，钢中夹杂物主要是不规则的Al2O3夹杂，其中96.75%的夹杂物尺寸小于10μm。LF精炼结束后，大量夹杂物转变成以CaO-Al2O3-SiO2为主要成分的0～10μm复合氧化物夹杂。钢水从VD真空精炼炉向中间包转移过程中，由于保护性浇注效果差，二次氧化严重造成钢水夹杂逐渐增多，其中夹杂物主要为球形的mCaO·nAl2O3复合夹杂物。铸坯中99.65%的夹杂物尺寸小于10μm，其中大部分为球形钙铝酸盐夹杂物，还有少量球状硅铝酸钙复合夹杂物。轧材中98.77%的夹杂物尺寸小于10μm。通过对炼钢过程中各工序的工艺优化，可实现对夹杂物的有效控制，从而确保50Cr5MoV合金铸钢的产品质量。

The total amount of oxygen content and the category of inclusions in 50Cr5MoV forged steel roll by the route of EBT→LF→VD were analyzed . The results show the average w(T[O]) was 0.004 7%after LF refining and 0.001 4%af-ter VD refining,and 0.001 55%in tundish,0.001 8%in billet and 0.001 0%in rolled steel on average. During the initial stage of LF refining,the inclusions in steel mainly are irregular forms of Al2O3. 96.75%of the inclusions have the diame-ters less than 10μm.After the LF refining,most of the inclusions are 0-10μm diameters of compound oxide inclusions, predominantly containing CaO-Al2O3-SiO2.During the transfer of steel from VD treatment to tundish,the protective cast-ing is awful,and the severe reoxidation contributes to the growing amount of inclusions,mainly containing spherical mCaO·nAl2O3 compound oxide inclusions 99.65%of the inclusions in the steel slab are less than 10μm. Most of them are spherical calcium-aluminate compound inclusion,with a few spherical calcium aluminosilicate compound inclusion. And 98.77%of the inclusions in rolled steel have diameters less than 10μm Therefore,the process optimization of every process of iron making,could contribute to the effective control of inclusions and ensure the quality of 50Cr5MoV forged steel roll.