Zinc-coated steel for press hardening applications and method of production
AssigneeAK Steel Properties, Inc.
InventorsRalph Mutschler, Grant Thomas, Paul V. Janavicius, Luis G. Garza-Martinez
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Abstract
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 α-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.
Claims20
A method of producing steel, the method comprising the steps of:
- galvannealing the steel to form a coating on the steel;
- and
- subjecting the galvannealed steel to a pre-alloying heat treatment conducted at a temperature between about 850° F. and about 950° F. prior to hot stamping.
A steel having a galvannealed coating, wherein the galvannealed coating comprises an Fe level between about 15 wt % and about 25 wt % in response to a pre-alloying heat treatment conducted at a temperature between about 850° F. and about 950° F. in an open coil annealing process.
Dependencies are inferred from the claim text.