The steel B7(40CrMnMo) for high strength heat-resisting bolts is produced by 70 t Consteel UHP arc furnace - 70 t ladle refining furnace - 4 strand 150 mm×150 mm concasting- continuous rolling process at Egang. The charge of arc furnace is 30% pig iron + 70% quality scrap of which the preheating temperature is no less than 600 ℃. The ex- amination shows that the chemical compositions of products are controlled in range of 0.39~0.42C

0.86～0.91Mn

0.22 ~0.31Si

0.013～0.018P

0.005～0.013S

0.85～0.94Cr

0.16～0. 18Mo

0.019～0.028 Als

the ratings of segregation and porosity are 0.5~1.0

the ratings of inclusion are 0.5~2.0 and the grain size of φ18~史50 mm products are 8.5 ~9 which satisfy the using requirement of heat-resisting standardized piece bolts.