The steel making mill of Xingtai trial-produced grade XG835NH successfully a few days ago, which is a kind of high strength weathering steel product. Its domestic users mainly purchase foreign products recently.

　　This grade is applied to produce high strength weathering connecting bolts for its good properties of atmosphere corrosion resistance, high strength, delayed fracture resistance and low temperature impact resistance. It mainly replaces high strength low alloy bolts which is used to the connection of steel bridge structure. It is a new grade developed by Xingtai Steel and its downstream user together.

　　There are many different alloy elements with high content and narrow range of chemical content in this grade. Meanwhile, there shall be a serious control level for inclusions and a big difficulty to control surface quality of casting blank. Considering above properties, the technical personnel make a full discussion about process control details and procedure parameters. They also provide whole-process trace and guidance so that win a successful trial production which offer more options to replace the imported products.