Global Patent Index - EP 4368740 A1

EP 4368740 A1 20240515 - FERRITIC FREE-CUTTING STAINLESS STEEL MATERIAL

Title (en)

FERRITIC FREE-CUTTING STAINLESS STEEL MATERIAL

Title (de)

FERRITISCHES, FREI SCHNEIDENDES EDELSTAHLMATERIAL

Title (fr)

MATÉRIAU EN ACIER INOXYDABLE FERRITIQUE DE DÉCOLLETAGE

Publication

EP 4368740 A1 20240515 (EN)

Application

EP 23207410 A 20231102

Priority

JP 2022177092 A 20221104

Abstract (en)

The present invention relates to a ferritic free-cutting stainless steel material having a component composition contains: in terms of mass%, 10.0%≤Cr≤25.0%, 0.2%≤Mn≤2.0%, 0.30%≤Al≤2.50%, 0.02%≤Si≤0.60%, and 0.10%≤S≤0.45%, and further two or more selected from the group consisting of 0.03%≤Pb≤0.40%, 0.03%≤Bi≤0.40%, and 0.01%≤Te≤0.10%, with a balance being Fe and unavoidable impurities. The component composition satisfies: 900([C] + [N]) + 170[Si] + 12[Cr] + 30[Mo] + 10[Al] < 300, and ([Cr] + [Mo] + 1.5[Si] + 4[Al])/([Ni] + 0.5[Mn] + 30[C] + 30[N]) ≥ 7. The ferritic free-cutting stainless steel material contains sulfides having a circle equivalent diameter of 1.5 µm or more, and the sulfides have an average circle equivalent diameter of 3.0 to 15.0 µm, an average aspect ratio of 2.5 or less, and an area ratio of 0.5 to 2.0%, and the maximum value of Vickers hardness of 170 HV or less.

IPC 8 full level

C22C 38/60 (2006.01); C21D 6/00 (2006.01); C21D 6/02 (2006.01); C21D 7/13 (2006.01); C21D 8/00 (2006.01); C21D 8/06 (2006.01); C21D 9/52 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/18 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/54 (2006.01)

CPC (source: EP US)

C21D 1/84 (2013.01 - US); C21D 6/002 (2013.01 - EP); C21D 6/004 (2013.01 - EP US); C21D 6/005 (2013.01 - US); C21D 6/008 (2013.01 - US); C21D 6/02 (2013.01 - EP); C21D 7/13 (2013.01 - EP); C21D 8/005 (2013.01 - EP); C21D 8/065 (2013.01 - EP US); C21D 9/52 (2013.01 - EP); C21D 9/525 (2013.01 - US); C22C 38/001 (2013.01 - EP US); C22C 38/002 (2013.01 - EP US); C22C 38/004 (2013.01 - EP US); C22C 38/02 (2013.01 - EP US); C22C 38/04 (2013.01 - EP US); C22C 38/06 (2013.01 - EP US); C22C 38/18 (2013.01 - EP); C22C 38/42 (2013.01 - EP US); C22C 38/44 (2013.01 - EP US); C22C 38/54 (2013.01 - EP US); C22C 38/60 (2013.01 - EP US); C21D 2211/005 (2013.01 - US)

Citation (applicant)

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 ME MK MT NL NO PL PT RO RS SE SI SK SM TR

Designated extension state (EPC)

BA

Designated validation state (EPC)

KH MA MD TN

DOCDB simple family (publication)

EP 4368740 A1 20240515; JP 2024067206 A 20240517; US 2024150881 A1 20240509

DOCDB simple family (application)

EP 23207410 A 20231102; JP 2022177092 A 20221104; US 202318384167 A 20231026