(1250) Nonmetallic inclusion control of steel for tirecord and saw wire

摘要

Steel rod for tirecord wire is designed for high tensile properties. It must be drawn to ultra-fine size in order to reduce the tire weight without the breakage during drawing and twisting. Recently, steel rod for tirecord wire is being developed as saw wire to cut silicon ingots. Saw wire must not be broken during cutting the silicon ingots. This breakage of wire is mainly caused by nonmetallic inclusion in the steel rod. Many activities are performed to control the nonmetallic inclusion in Pohang Mill, POSCO. The chemical composition of nonmetallic inclusion with a low melting temperature and good drawability was controlled. In addition, exogenous inclusions with large size were reduced by managing the ferroalloys and refractory. New extraction method for inclusion analysis was developed to precisely evaluate the harmful inclusions connected with the wire breakage.