Low Cost HSLA-Steel Produced by BOF-CSP Process: A Primary Study on Ti Microalloyed Pipe Line Steel

摘要

The mechanical properties, microstructure, precipitates and strengthening mechanism of Ti microalloyed low cost HSLA steel produced by BOF-CSP were investigated. The yield strength and tensile strength of the steel were 650 MPa and 725 MPa, respectively, with fine gains of polygon ferrite and granular bainite microstructure. The mechanical properties such as elongation and cold bending were good. The dispersed precipitates of steel were mainly of Nb(C,N)and Ti(C,N) which contribution 190 MPa for strengthen in the Nb-Ti alloyed steel.