PRODUCTION OF LARGE-SCALE EASY-TO-QUENCH STRAIGHT COLD HEADING STEEL
In response to the problem of insufficient hardenability of large-sized SWRCH35K,measures such as optimizing its composition system,reducing Si content,controlling C and Mn content,and adding Cr and B elements are adopted to solve the problem.By improving the cleanliness of molten steel,adopting appropriate superheat,and using aluminum carbon water nozzles,the problem of"sleeve hole"in continuous casting has been solved.At the same time,by controlling rolling and cooling,a suitable ferrite ratio and a small and uniform pearlite structure have been obtained.The tensile strength is higher than that of the original SWRCH35K,and the hardness value is 83.5(HRB).After direct processing,it undergoes quenching and tempering treatment to ensure uniform hardness of the core and edges,with a hardness of 31～32(HRC),effectively solving the problem of insufficient quenching in the core of large-sized cold heading steel.
万方数据
维普
