EP 3020841 B1 20180822 - COIL SPRING, AND METHOD FOR MANUFACTURING SAME
Title (en)
COIL SPRING, AND METHOD FOR MANUFACTURING SAME
Title (de)
SPIRALFEDER UND VERFAHREN ZUR HERSTELLUNG DAVON
Title (fr)
RESSORT HÉLICOÏDAL ET PROCÉDÉ DE FABRICATION DE CE DERNIER
Publication
Application
Priority
- JP 2013143514 A 20130709
- JP 2014068123 W 20140708
Abstract (en)
[origin: EP3020841A1] To provide a coil spring having excellent fatigue resistance. Disclosed is a coil spring made of steel, including (in % by mass, the same shall apply for a chemical composition): C: 0.40 to 0.70%; Si: 1.50 to 3.50%; Mn: 0.30 to 1.50%; Cr: 0.10 to 1.50%; V: 0.50 to 1.00%, and Al: 0.01% or less (excluding 0%), with the balance being iron and inevitable impurities, wherein an average crystal grain size number of prior austenite crystals in a depth of 0.3 mm from a surface is 11.0 or more, while a difference in grain size number between the respective prior austenite crystals is in a range of less than 3 from a grain size number observed at the maximum frequency, and wherein a carburized layer is provided in a depth of 0.30 to 1.00 mm from the surface, while an average Vickers hardness is 600 or higher at a position in a depth of (1/4) × diameter in the depth direction from the surface.
IPC 8 full level
C22C 38/00 (2006.01); C21D 1/06 (2006.01); C21D 1/773 (2006.01); C21D 6/00 (2006.01); C21D 9/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/34 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01); C23C 8/22 (2006.01)
CPC (source: EP US)
C21D 1/06 (2013.01 - EP US); C21D 1/773 (2013.01 - EP US); C21D 6/004 (2013.01 - EP US); C21D 6/005 (2013.01 - EP US); C21D 6/008 (2013.01 - EP US); C21D 9/02 (2013.01 - EP US); C22C 38/00 (2013.01 - EP US); C22C 38/002 (2013.01 - EP US); C22C 38/04 (2013.01 - EP US); C22C 38/06 (2013.01 - EP US); C22C 38/24 (2013.01 - EP US); C22C 38/26 (2013.01 - EP US); C22C 38/34 (2013.01 - EP US); C22C 38/46 (2013.01 - EP US); C22C 38/48 (2013.01 - EP US); C23C 8/22 (2013.01 - EP US)
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
DOCDB simple family (publication)
EP 3020841 A1 20160518; EP 3020841 A4 20170329; EP 3020841 B1 20180822; CN 105358726 A 20160224; CN 105358726 B 20170609; JP 2015017288 A 20150129; JP 5941439 B2 20160629; KR 101789944 B1 20171025; KR 20160018720 A 20160217; US 2016160306 A1 20160609; WO 2015005311 A1 20150115
DOCDB simple family (application)
EP 14823237 A 20140708; CN 201480039266 A 20140708; JP 2013143514 A 20130709; JP 2014068123 W 20140708; KR 20167000388 A 20140708; US 201414903975 A 20140708