Development of Low Silicon Galvannealed TRIP Steel with High Strength

Abstract

  Hot-dip galvannealed sheet (GA) were developed from the automotive industry. It has high strength of 590 MPa grade in tensile strength. However, in order succeeds from automobile industry, the microstructure and galvannealing behavior of galvannealed TRIP steel sheets must be strictly controlled. The metal where the silicon content is high has problems with weld-ability, zinc coating and reduction of retained austenite volume fraction after galvannealing process. The main purpose of this study is to solve the problem as indicated above.