Patent ID: 9597988
Date: 2017-03-21
CPC Classifications: B23K,B60N

Claim:
1. A method of laser welding together a vehicle seat having different steel grades, the method comprising the steps of: providing a first seat structure having a first end, an opposed second end, an outer surface and an inner surface, the first seat structure made from a first steel grade; providing a second seat structure having a first end, an opposed second end, an outer surface, and an inner surface, the second seat structure made from a second steel grade; positioning the first seat structure first end adjacent the second seat structure first end to create a weld zone area, wherein at least a portion of the first seat structure first end overlaps at least a portion of the second seat structure first end; selecting a filler material having a composition that will create a weld joint between the first seat structure first end, the second seat structure first end and the filler material such that the weld joint has a predetermined microstructure; positioning the filler material adjacent the weld zone area; and directing a laser beam at the weld zone area to form a weld joint between the first seat structure first end, the second seat structure first end, and the filler material, wherein the weld joint has a predetermined microstructure to form the vehicle seat; wherein the first steel grade is made from TWIP steel; wherein the second steel grade is made from low to medium carbon steel; wherein the welding joint has an austenitic microstructure; and wherein the filler material is a STS310 filler material having a nickel and chromium equivalency that is austenitic.