TRIP STEEL SHEET WITH EXCELLENT GALVANIZING PROPERTY AND METHOD OF MANUFACTURING THE STEEL SHEET

摘要

A TRIP steel sheet having excellent galvanizing properties using a change in thermal-treatment temperature and a manufacturing method thereof are disclosed. The manufacturing method of the TRIP steel sheet according to the present invention includes a hot-rolling step which forms hot-rolled steel by reheating, hot-rolling, cooling, and winding a steel slab; a cold-rolling step which cold-rolls the hot-rolled steel after pickling; an annealing step which rapidly heats the cold-rolled steel to a temperature of 800-950°C for 40-80 seconds and then thermally treats the steel at a temperature of 800-950°C; and an austempering step which isothermally transforms the annealed steel in a bainite transformation temperature range.