US 11,851,767 B2
Rust prevention member and method for producing same
Tsukasa Niwa, Aichi (JP); Toshihiro Sugiura, Aichi (JP); Yoshiki Hiramatsu, Aichi (JP); and Hiroki Yoshida, Aichi (JP)
Assigned to YUKEN INDUSTRY CO., LTD., Aichi (JP)
Appl. No. 16/626,868
Filed by YUKEN INDUSTRY CO., LTD., Aichi (JP)
PCT Filed Jun. 26, 2018, PCT No. PCT/JP2018/024107
§ 371(c)(1), (2) Date Dec. 26, 2019,
PCT Pub. No. WO2019/004163, PCT Pub. Date Jan. 3, 2019.
Claims priority of application No. 2017-127192 (JP), filed on Jun. 29, 2017.
Prior Publication US 2020/0115803 A1, Apr. 16, 2020
Int. Cl. C23C 10/52 (2006.01); C23C 22/78 (2006.01); C23C 22/82 (2006.01); C23C 28/00 (2006.01); C25D 3/22 (2006.01); C23C 10/28 (2006.01)
CPC C23C 22/78 (2013.01) [C23C 22/82 (2013.01); C23C 28/00 (2013.01); C25D 3/22 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A rust prevention member comprising:
a base material;
a zinc-based plating layer provided on the base material; and
a chemical conversion coating film provided on the zinc-based plating layer and containing Si, wherein
the chemical conversion coating film has a Si-rich region in which an atomic ratio of a Si content to a Zn content is 1 or more on a surface layer side with a thickness of 100 nm or more, and
the chemical conversion coating film has a gradient region with a thickness of 50 nm or more in which the Zn content increases toward the zinc-based plating layer while the Si content decreases toward the zinc-based plating layer between the Si-rich region and the zinc-based plating layer,
wherein the following Expression (2-1) and the following Expression (2-2) are satisfied in the gradient region,
[Si]/[Zn]<1  (2-1)
[Zn]≤0.8×[Zn]0  (2-2)
wherein [Si] is a Si content in atomic % in the chemical conversion coating film, [Zn] is a Zn content in atomic % in the chemical conversion coating film, and [Zn]0 is a Zn content in atomic % in the zinc-based plating layer, and
wherein the Si-rich region and the gradient region are continuous in a thickness direction.