Study on inclusions in automotive gear steel 8620RH
Oxide inclusion (B inclusion) in the rod of automotive gear steel 8620RH produced in No.1 steelmaking plant of Fushtn Special Steel Shares Co.,Ltd.was excessive.The composition of inclusions was analyzed with SEM.The results showed that there were two kinds of inclusions in the steel,that were the deoxidation or reoxidation products mainly composed of magnesia-alumina spinel or A12 O3,and the complex non-metallic inclusions caused by slag entrapment.Meanwhile,the sources of two kinds of inclusions were analyzed and the improvement measures were taken,so that the qualified rate of B inclusion in the automotive gear steel 8620RH was increased from 96.4 % to 99.7 %.