HOT-ROLLED STEEL SHEET - NIPPON STEEL & SUMITOMO METAL CORP

Title:

HOT-ROLLED STEEL SHEET

Document Type and Number:

WIPO Patent Application WO/2018/179387

Kind Code:

A1

Abstract:

A hot-rolled steel sheet, wherein: the chemical composition, in mass%, is C: 0.07-0.22%, Si: 1.00-3.20%, Mn:0.80-2.20%, Al: 0.010-1.000%, N≤0.0060%, P≤0.050%, S≤0.005%, Ti: 0-0.150%, Nb: 0-0.100%, V: 0-0.300%, Cu: 0-2.00%, Ni: 0-2.00%, Cr: 0-2.00%, Mo: 0-1.00%, B: 0-0.0100%, Mg: 0-0.0100%, Ca: 0-0.0100%, REM: 0-0.1000%, Zr: 0-1.000%, Co: 0-1.000%, Zn: 0-1.000%, W: 0-1.000%, Sn: 0-0.050%, balance: Fe and impurities; the metal structure located at 1/4W or 3/4W from the edge face of the steel sheet and 1/4t or 3/4t from the surface is, in area%, retained austenite: greater than 2% to 10%, martensite≤2%, bainite: 10-70%, pearlite≤2%, balance: ferrite; the mean equivalent circular diameter of the metal phases made of retained austenite/martensite is 1.0-5.0 µm; the mean value for the shortest distance between adjacent metal phases is at least 3 µm; and the standard deviation for nano-hardness is 2.5 GPa or less.

Inventors:

YOKOI TATSUO (JP)
YOSHIKAWA NOBUO (JP)
YONEMURA SHIGERU (JP)
OOTSUKA KAZUYA (JP)

Application Number:

PCT/JP2017/013743

Publication Date:

October 04, 2018

Filing Date:

March 31, 2017

Export Citation:

Click for automatic bibliography generation Help

Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)

International Classes:

C22C38/00; C22C38/58; C21D9/46

Domestic Patent References:

WO2011148490A1	2011-12-01
WO2016133222A1	2016-08-25

Foreign References:

JP2005256066A	2005-09-22
JP2003321738A	2003-11-14
JP2012251201A	2012-12-20
JP2008266778A	2008-11-06
JPH10158735A	1998-06-16
JP2009084648A	2009-04-23
JP2011225941A	2011-11-10
JP2002129286A	2002-05-09
JP2001152254A	2001-06-05
JP2015124411A	2015-07-06
JP2009019265A	2009-01-29

Other References: