Microstructure and Property of 700MPa Ti Microalloyed High Strength Steel Produced by EAF-CSP

Abstract

High strength steel ZJ700MC with yield strength grade of 700 MPa was successfully developed by Ti micro-alloyed technology in the EAF-CSP line at Zhujiang Steel. The composition design, smelting process, continuous casting and rolling process of the steel, as well as the mechanical properties of the hot-rolled product are introduced in the paper. An analysis on the strengthening mechanism of the high strength steel shows that the enhanced strength and toughness of the steel were caused by the refinement of ferrite grain and the precipitation strengthening of TiC.

Development of Micro-Alloying Ultra-Fine Grain High Strength Steel Produced by EAF-TSCR

“…Making use of the high N content in EAF steel, it is far from enough just to reply on the 0.007% N content of EAF steel, VN alloy is needed to add into the steel to increase the N content to over 0.020%. The chemical composition of experimental steel is shown in table 1 [3,4,5].…”