Metallic component and method of reducing liquid metal embrittlement using low aluminum zinc bath

Patent metadata

Field	Value
Publication number	US-11433646-B2
Application number	US-201916394060-A
Country	US
Kind code	B2
Filing date	Apr 25, 2019
Priority date	Apr 25, 2019
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

A metallic component includes a core formed of steel. A zinc alloy layer is disposed on the core. The zinc alloy layer is formed of zinc and a very small amount of aluminum, such as 0.14 weight percent or less. A method of creating a component includes providing a steel core, providing a zinc bath consisting of essentially of 0.01 to 0.14 weight percent aluminum, and hot dipping the steel core into the zinc bath to form a zinc coating on the steel core resulting in a zinc-coated steel component. The aluminum may be provided in even lower contents, such as less than 0.08 weight percent, or even less than 0.05 weight percent. The zinc-coated steel component may then be spot welded to another component without first annealing the zinc-coated component. Rather, heat treating is performed locally at the weld joint by the welding procedure alone.

First claim

What is claimed is:

1. A metallic component comprising:
a core formed of steel;
a zinc alloy layer comprising zinc and aluminum disposed on the core, the zinc alloy layer comprising a majority of zinc and less than 0.05 weight percent aluminum; and
an inhibition layer disposed between the zinc alloy layer and the core, the inhibition layer contacting each of the core and the zinc alloy layer, wherein the inhibition layer has an average thickness that is greater than or equal to about 10 nanometers to less than or equal to about 30 nanometers.

2. The metallic component of claim 1 , the core comprising transformation-induced plasticity (TRIP) steel.

3. The metallic component of claim 1 , wherein the zinc alloy layer consists essentially of 0.01 to less than 0.05 weight percent aluminum and the balance zinc.

4. The metallic component of claim 1 , further comprising a second component spot welded to the core having the zinc alloy layer disposed thereon.

5. A metallic component comprising:
a core formed of steel;
a zinc alloy layer comprising zinc and aluminum disposed on the core, the zinc alloy layer comprising a majority of zinc and less than or equal to 0.08 weight percent aluminum; and
an inhibition layer disposed between the zinc alloy layer and the core, the inhibition layer contacting the core and the zinc alloy layer, and the inhibition layer having an average thickness of greater than or equal to about 10 nanometers to less than or equal to about 30 nanometers.

6. The metallic component of claim 5 , wherein the zinc alloy layer comprises less than or equal to 0.05 weight percent aluminum.

7. The metallic component of claim 6 , wherein the zinc alloy layer consists essentially of 0.01 to 0.05 weight percent aluminum and the balance zinc.

8. The metallic component of claim 5 , the core being formed of transformation-induced plasticity (TRIP) steel.

9. The metallic component of claim 5 , wherein the zinc alloy layer consists essentially of 0.01 to 0.08 weight percent aluminum and the balance zinc.

10. The metallic component of claim 5 , further comprising a second component spot welded to the steel core having the zinc alloy layer disposed thereon.

11. The metallic component of claim 5 , the core being formed of a twinning-induced plasticity (TWIP) steel.

12. A method of creating a component, the method comprising:
providing a steel core;
providing a zinc bath consisting of essentially of 0.01 to 0.08 weight percent aluminum and the balance zinc; and
hot dipping the steel core into the zinc bath to form a zinc coating on the steel core resulting in a zinc-coated steel component, the component comprising:
a core formed of steel;
a zinc alloy comprising zinc and aluminum layer disposed on the core, the zinc alloy layer comprising a majority of zinc and less than 0.08 weight percent aluminum; and

an inhibition layer disposed between the zinc alloy layer and the core, the inhibition layer contacting the core and the zinc alloy layer, and the inhibition layer having an average thickness of greater than or equal to about 10 nanometers to less than or equal to about 30 nanometers.

13. The method of claim 12 , further comprising refraining from annealing the zinc-coated steel component in an annealing furnace after the step of hot dipping the steel core into the zinc bath.

14. The method of claim 12 , further comprising forming the steel core from a transformation-induced plasticity (TRIP) steel.

15. The method of claim 12 , wherein the zinc bath consists essentially of:
0.01 to 0.05 weight percent aluminum;
0 to 0.001 weight percent trace elements;
and the balance zinc.

16. The method of claim 12 , further comprising spot welding the zinc-coated steel component to a second component to create an assembly having a spot weld joint.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Enloe Charles
• Karagoulis Michael J
• Horvath Curt D

Classifications

• C23C2/40

  Plates; Strips · CPC title

• B32B15/013 Primary

  one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium · CPC title

• Y10T428/12965

  Both containing 0.01-1.7% carbon [i.e., steel] · CPC title

• C23C28/023

  only coatings of metal elements only · CPC title

• B23K2103/04

  Steel {or steel} alloys · CPC title