LF喂Ca线改善易切削钢Y1Cr13硫化物形貌的工艺实践

试验钢Y1Cr13(/%:0.11C,0.31Si,1.14Mn,0.024P,0.28S,12.43Cr,0.001 1Ca,0.012Al,0.008 40,Mn/S 4.07)的冶金流程为60 t AOD-LF-150 mm×150 mm坯连铸-轧制Φ12 mm材。原未加Ca的LF精炼渣碱度为1.7～2.1,用Fe-Si脱氧,T0]为0.012%～0.015%,而改进的加Ca工艺为LF FeSi脱氧后补加Al线深脱氧,TO]为0.007%～0.010%,加Ca线进行夹杂物变性处理。结果表明,加入实芯钙线使钢中长条型硫化物变性为球型或纺锤型,线材产品中硫化物长度由最长的160μm缩短为100μm,纺锤形硫化物(长宽比≤3)所占比例由52.90%提高至72.09%,提高了产品切削性能。

Process Practice of Morphology Modification of Sulfide in Free Cutting Steel YlCrl3 by Feeding Ca Wire during LF ReHning

Metallurgical flowsheet of tested steel Y1Crl3 (/% ： 0.11C, 0.31 Si, 1.14Mn, 0.024P, 0.28S, 12.43Cr, 0.001 ICa, 0. 012A1, 0.008 40, Mn/S 4. 07) is 60 t AOD-LF-150 mm x 150 mm billet casting-rolled to Φ12 mm products. In original LF refining without adding Ca, the refining slag basicity is 1.7 ~ 2.1 and the TO] is 0.012% ~ 0. 015% by only using Fe-Si to deoxidation, while in the improved, adding Ca process, after LF Fe-Si deoxidation adding the Al wire is supplied again to deep deoxidation, the TO] is 0.007% ~0. 010% , and the Ca wire is fed to modify the inclusions in liquid. Results show that with adding core calcium wire the long stripe sulfide is modified to spherical or spindle sulfide, the max length of sulfide in products reduces to 100 μm from original 160 μmμm, the ratio of spindle sulfide with length/width ≤3 increases to 72.09% from original 52.90% markedly to improve the cutting performance of products.