Zinc-coated steel for press hardening application and method of production

摘要

A zinc-coated steel may be produced by performing a pre-alloying heat treatment after galvannealing the steel and prior to the hot stamping the steel. The pre-alloying heat treatment is conducted at a temperature between about 850°F and about 950°F in an open coil annealing process. The pre-alloying heat treatment allows for shorter time at the austenitization temperature to form a desired a-Fe phase in the coating by increasing the concentration of iron. This also decreases the loss of zinc, and a more adherent oxide exists after hot stamping.