MATERIAL AND PROCESS ENGINEERING APPLYING TO CASTING AND ROLLING OF LONG PRODUCTS IN ENGINEERING STEEL GRADES

Increasing demands on the properties, faultlessness and economic effic iency of long products in engineering steel grades require extensive m aterial and process engineering. Modern tools for material research, e .g. laboratory simulation techniques process-modelling, can be applied to develop process parameters related to the material behaviour. This is shown by means of three examples. High-temperature-ductility is de termined by hot tensile tests after partial remelting of the samples. Hot cracking during continuous casting can be reduced if process condi tions, which minimize the stress in the strand shell, in the temperatu re ranges with reduced material ductility or if the chemical compositi on of a steel is improved to reduce its susceptibility to hot cracking . Segregations in concast-blooms and bars are analyzed by computer-con trolled microprobes. The influence of segregations on the microstructu re and properties of bars can be minimized by suitable heating up of t he material. Adequate parameters tor normalizing rolling of quenched a nd tempered steels can be developed by dilatometer simulation.