MANUFACTURING METHOD OF TRANSFORMATION INDUCED PLASTICITY STEEL WITH EXCELLENT COATABILITY AND COATING ADHESION

摘要

Disclosed are a TRIP steel capable of ensuring excellent coatability and coating adhesion by changing a temperature rising pattern at the time of annealing heat treatment process, and a method for manufacturing the same. According to the present invention, the method for manufacturing TRIP steel includes: a hot-rolling step for forming hot rolled steel by reheating, hot-rolling, and coiling a steel slab containing silicon (Si) and manganese (Mn); a cold-rolling step for cold-rolling the hot-rolled steel after pickling; an annealing heat treatment step for annealing heat treating the cold-rolled steel up to a temperature of 750-850C after heating the cold-rolled steel in a radiant tub heating furnace up to a temperature of 450-650C and maintaining the heated steel for 50-300 seconds in a section of maintaining at a temperature of 450-650C; and a galvanizing step for galvanizing the annealing heat-treated steel at a temperature of 440-480C.