Production Process Study Of J55 Oil Casting Steel For Xinjiang Bayi Iron And Steel Company

Xinjiang bayi iron and steel company is located in oil-rich province of Xinjiang possessing the unique geographical advantages.Therefore,the research and development of J5 5 oil well special casing are vital for both product upgrades and benefits improvements of the industry.Combining with the practical scientific research work of equipment upgrading and new product development,this paper studies the relevant issues of J55 steel grade development which is from 1750 hot rolling production line in bayi iron and steel industry.Main results are as follows:(1)Make sure conditions of J55 steel grade including chemical composition,heating system,hot rolling process and cooling process after rolling.Conducting structure property analysis of try rolling products proves that products microstructures are ferrite and pearlite,and indicates that the performances of yield strength,tensile strength,yield-strength ratio and break elongation satisfy the government standard requirement.(2)Four surface quality problems existing in the process of producing J55 oil well special casing are analyzed to find the accident cause,and then formulate prevention measures.Adjusting descaling header height in the finishing rolling area can effectively solve the oxide iron scale problem of J55 surface.Changing the roughing vertical roll shape that the roll ring is removed can effectively solve the scarring problem of J55 surface.The J55 upper surface scratch problem can be solved availably by adjusting roll guide height of the guide plate in F5 inlet side of finish rolling and decreasing looper height.The lower surface scratch problem can be solved availably by optimizing the point inspection mechanism of looper rolls.(3)Through analyzing the generating reasons of uneven lateral performances of J55 oil well special casing,corresponding improvement measures are carried out.Lateral flow difference is reduced with the optimization for header flow regulation standards.Adjusting water yield of header pipe' upper and down with the ratio of 1:1.3,which is located in encryption cooling section of the first seven zone of cold layer makes the overall flow turn down 20%.After calculation,the top cooling head adjustment is determined,which is implemented with the 1/2-4/5 of glass tube height,and the bottom cooling head adjustment is determined with its water column height reaching 2/3-4/5 of plate height.Side spray water collection system is rectified and side spray angle is controlled.