Manufacturing of the YS180 MPa Grade Hot Dipping Galvanizing BH-Steel H180BD for Automotive Exposed Panels

摘要

Considering the metallurgy characteristic of baking hardening steels,the YS180 MPa grade baking hardening steel was developed by controlling chemical composition and optimizing smelting,hot-rolling and galvanizing processes. The results show the steel,with the 180-240 MPa yield strength,300-360 MPa tensile strength,R≥1.5,N≥0.16 and BH2 ≥30 MPa,has the excellent formability and good bakehardening behavior and easing galvanizing property of uniform coating. After aging 145 days,the tensile curve of the steel is still smooth,and except the decreasing of R value,other mechanical properties remain constant. The steel is well used in automobiles for exposed panels with excellent aging behavior within room temperature.