Global Patent Index - EP 1122331 B1

EP 1122331 B1 20030326 - Process of nitriding and/or carbonitriding of high-alloyed steel

Title (en)

Process of nitriding and/or carbonitriding of high-alloyed steel

Title (de)

Verfahren zum Nitrieren und/oder Nitrocarburieren von höher legierten Stählen

Title (fr)

Procédé pour la nitruration et/ou carbonitruration d' acier fortement allié

Publication

EP 1122331 B1 20030326 (DE)

Application

EP 00102359 A 20000204

Priority

EP 00102359 A 20000204

Abstract (en)

[origin: US6328819B1] A method is provided for heat treatment of metal workpieces obtain a substantially uniform nitride layer, even in workpieces comprising high alloy iron articles. The following method steps are provided:a) heating the workpieces to a temperature between 400° C. and 500° C. in a gas atmosphere comprising only ammonia;b) continuing to heat the workpieces to a temperature between 500° C. and 700° C. in a gas atmosphere containing ammonia and an added oxidizing agent;c) maintaining the workpieces at this temperature and in this gas atmosphere for a period of between 0.1 hour and 5 hours;d) continuing to maintain the workpieces at this temperature for a period of between 1 hour and 100 hours in a gas atmosphere containing ammonia or containing ammonia and a carbon-releasing substance; and,e) cooling the workpieces to room temperature.

IPC 1-7

C23C 8/34; C21D 1/613; C21D 6/00

IPC 8 full level

C23C 8/26 (2006.01); C23C 8/34 (2006.01)

CPC (source: EP US)

C23C 8/26 (2013.01 - EP US); C23C 8/34 (2013.01 - EP US)

Designated contracting state (EPC)

AT CH DE FR GB IT LI

DOCDB simple family (publication)

EP 1122331 A1 20010808; EP 1122331 B1 20030326; AT E235581 T1 20030415; DE 50001540 D1 20030430; US 6328819 B1 20011211

DOCDB simple family (application)

EP 00102359 A 20000204; AT 00102359 T 20000204; DE 50001540 T 20000204; US 56269500 A 20000428