Global Patent Index - EP 3674433 A4

EP 3674433 A4 20200729 - HIGH-STRENGTH STEEL SHEET FOR SOUR-RESISTANT LINE PIPE, AND HIGH-STRENGTH STEEL PIPE USING SAME

Title (en)

HIGH-STRENGTH STEEL SHEET FOR SOUR-RESISTANT LINE PIPE, AND HIGH-STRENGTH STEEL PIPE USING SAME

Title (de)

HOCHFESTES STAHLBLECH FÜR SAUERGASRESISTENTE LEITUNGSROHRE UND HOCHFESTES STAHLROHR DAMIT

Title (fr)

TÔLE D'ACIER À HAUTE RÉSISTANCE POUR TUYAU DE CANALISATION RÉSISTANT À L'ACIDITÉ ET TUYAU EN ACIER À HAUTE RÉSISTANCE L'UTILISANT

Publication

EP 3674433 A4 20200729 (EN)

Application

EP 17929314 A 20171019

Priority

JP 2017037891 W 20171019

Abstract (en)

[origin: EP3674433A1] The present disclosure provides a high strength steel plate for sour-resistant line pipes that has excellent HIC resistance in which variation in the HIC resistance in the plate width direction is suppressed. A high strength steel plate for sour line pipes disclosed herein includes a chemical composition containing C, Si, Mn, P, S, Al, and Ca in predetermined amounts, with the balance being Fe and inevitable impurities, in which in a cross-section perpendicular to a rolling direction of the steel plate, the number of Mn-concentrated spots that are approximated to an elliptical shape having a major axis length of more than 1.5 mm, in a measuring region located ±5 mm from a plate thickness center toward a plate thickness direction, is 3 or less per 100 mm in length in a plate width direction, HIC resistance is 10 % or less in terms of CAR at a W/4 position, a W/2 position, and a 3W/4 position from one end in the plate width direction of the steel plate, where W denotes a plate width, variation in the HIC resistance in the plate width direction in terms of 3σ is 5 % or less when σ denotes a standard deviation of CARs, and a tensile strength is 520 MPa or more.

IPC 8 full level

C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/18 (2006.01); C22C 38/58 (2006.01)

CPC (source: EP KR)

C21D 8/0226 (2013.01 - EP); C21D 8/0263 (2013.01 - EP); C21D 9/46 (2013.01 - EP); C22C 38/02 (2013.01 - EP); C22C 38/04 (2013.01 - EP KR); C22C 38/06 (2013.01 - EP); C22C 38/08 (2013.01 - EP); C22C 38/12 (2013.01 - EP); C22C 38/14 (2013.01 - EP); C22C 38/16 (2013.01 - EP); C22C 38/18 (2013.01 - EP); C22C 38/24 (2013.01 - KR); C22C 38/26 (2013.01 - KR); C22C 38/38 (2013.01 - KR)

Citation (search report)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

Designated extension state (EPC)

BA ME

DOCDB simple family (publication)

EP 3674433 A1 20200701; EP 3674433 A4 20200729; BR 112020007057 A2 20201006; BR 112020007057 B1 20220712; CN 111247261 A 20200605; JP 6798565 B2 20201209; JP WO2019077725 A1 20191114; KR 102497363 B1 20230208; KR 20200058490 A 20200527; WO 2019077725 A1 20190425

DOCDB simple family (application)

EP 17929314 A 20171019; BR 112020007057 A 20171019; CN 201780095998 A 20171019; JP 2017037891 W 20171019; JP 2018564993 A 20171019; KR 20207011797 A 20171019