	US 12,221,707 B2
	Acid-resistant steel sheet and manufacturing method therefor
Minho Jo, Pohang-si (KR); Byoung Ho Lee, Pohang-si (KR); and Young-Kwang Hong, Pohang-si (KR)
Assigned to POSCO CO., LTD, Pohang-si (KR)
Appl. No. 17/297,938
Filed by POSCO, Pohang-si (KR)
PCT Filed Nov. 26, 2019, PCT No. PCT/KR2019/016378 § 371(c)(1), (2) Date May 27, 2021, PCT Pub. No. WO2020/111734, PCT Pub. Date Jun. 4, 2020.
Claims priority of application No. 10-2018-0153136 (KR), filed on Nov. 30, 2018.
Prior Publication US 2022/0042179 A1, Feb. 10, 2022
Int. Cl. C21D 9/46 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C23F 11/04 (2006.01)

CPC C23F 11/04 (2013.01) [C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0263 (2013.01); C21D 9/46 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01)]

5 Claims

1. An acid-resistant hot-rolled steel sheet comprising,

by wt %, equal to or less than 0.1% of C excluding 0% and 2.0 to 4.0% of Si, and a remainder of Fe and inevitable impurities,

wherein the content of Si of the surface portion by the inward depth of up to 10 μm from the surface of the steel sheet is equal to or greater than 15 wt %.