EP 3375894 A1 20180919 - GAS QUENCHING METHOD
Title (en)
GAS QUENCHING METHOD
Title (de)
VERFAHREN ZUM ABSCHRECKEN VON GAS
Title (fr)
PROCÉDÉ DE TREMPE GAZEUSE
Publication
Application
Priority
JP 2015081698 W 20151111
Abstract (en)
A gas quenching method of the present invention includes a first stage (t1 to t2) at which a workpiece is subjected to a rapid cooling by forcibly circulating a cooling gas, a second stage (t2 to t3) at which the circulation of the cooling gas is stopped and pressure is reduced inside the furnace to conduct heat insulation, and a third stage (as from t3) at which the workpiece is cooled again by the cooling gas. At the second stage, the workpiece is maintained at an intermediate temperature that is higher than martensite transformation start temperature, and, during this, temperature throughout the workpiece is made uniform. Therefore, it is possible to achieve a uniform quenching and suppress distortion caused by difference of the cooling speed.
IPC 8 full level
CPC (source: EP KR RU US)
C21D 1/19 (2013.01 - EP US); C21D 1/20 (2013.01 - EP RU US); C21D 1/613 (2013.01 - EP KR RU US); C21D 1/62 (2013.01 - EP KR US); C21D 1/767 (2013.01 - EP US); C21D 1/773 (2013.01 - RU); C21D 9/40 (2013.01 - EP US); C21D 1/22 (2013.01 - EP US); C21D 1/773 (2013.01 - EP US); C21D 2211/008 (2013.01 - EP KR 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
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
EP 3375894 A1 20180919; EP 3375894 A4 20180926; BR 112018009549 A2 20181106; CN 108350516 A 20180731; JP 6497446 B2 20190410; JP WO2017081760 A1 20180524; KR 102124030 B1 20200617; KR 20180075647 A 20180704; MX 2018005795 A 20180801; RU 2690873 C1 20190606; US 2018327874 A1 20181115; WO 2017081760 A1 20170518
DOCDB simple family (application)
EP 15908284 A 20151111; BR 112018009549 A 20151111; CN 201580084477 A 20151111; JP 2015081698 W 20151111; JP 2017549912 A 20151111; KR 20187015267 A 20151111; MX 2018005795 A 20151111; RU 2018121291 A 20151111; US 201515774749 A 20151111