Method of manufacturing martensitic stainless steel sheet using twin roll strip caster

Patent metadata

Field	Value
Publication number	US-9677159-B2
Application number	US-201414539386-A
Country	US
Kind code	B2
Filing date	Nov 12, 2014
Priority date	Nov 14, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A method of manufacturing a martensitic stainless steel sheet by allowing ingot steel to pass through two casting rolls rotating in opposing directions through a twin roll strip caster is provided. The method includes rolling a steel sheet cast between the casting rolls at a temperature of 1000 to 1200° C. and a draft percentage of 25 to 50% with a first roller, and rolling the steel sheet at a temperature of 800 to 1000° C. and a draft percentage of 5 to 15% with a second roller.

First claim

What is claimed is:

1. A method of manufacturing a martensitic stainless steel sheet by allowing ingot steel to pass through two casting rolls rotating in opposing directions through a twin roll strip caster, wherein a composition of the ingot steel comprises 0.5 to 0.8 weight % of carbon (C) and 12.5 to 14.5 weight % of chromium (Cr), the method comprising:
performing a first rolling process of rolling a steel sheet cast between the casting rolls, with a first roller, to induce recrystallization to occur; and
performing a second rolling process of rolling the steel sheet having been subjected to the first rolling process, with a second roller, to generate carbon precipitation sites.

2. The method of claim 1 , wherein the first rolling process is performed at a temperature of 1000 to 1200° C. at a draft percentage of 25 to 50%.

3. The method of claim 1 , wherein the second rolling process is performed at a temperature of 800 to 1000° C. at a draft percentage of 5 to 15%.

4. The method of claim 1 , wherein the steel sheet is cast between the casting rolls to have a thickness of 3 to 4 mm.

5. The method of claim 1 , wherein the steel sheet is rolled by the first roller to have a thickness of 2.2 to 2.5 mm.

6. The method of claim 1 , wherein the steel sheet rolled through the first rolling process is rolled by the second roller to have a thickness of 1.8 to 2 mm.

Assignees

• Posco

Inventors

• Ha Man-Jin
• Park Sung-Jin
• Song Byoung-Jun

Classifications

• C21D2211/008

  Martensite · CPC title

• C21D8/0215

  Rapid solidification; Thin strip casting · CPC title

• B22D11/1206

  for plastic shaping of strands (rolling mills B21B1/46) · CPC title

• C21D6/002

  containing Cr (C21D6/004 takes precedence) · CPC title

• C22C38/18 Primary

  containing chromium · CPC title