Title:
PRETREATMENT FOR NITRIDATION OF ALLOY CONTAINING CHROMIUM
Document Type and Number:
Japanese Patent JP3302812
Kind Code:
B2
Abstract:
PURPOSE: To easily perform uniform nitridation and soft nitridation of the surface of a chromium-contg. alloy by dipping the alloy in fused salts containing e.g. alkali metal hydroxide as the pretreatment.
CONSTITUTION: When the surface of an alloy containing chromium is subjected to nitridation or soft nitridation, the alloy is dipped as the pretreatment in p fused salts containing at least one of alkali metal hydroxides, alkali metal nitrates and alkali metal nitrites. One or more kinds of LiOH, NaOH, KOH are used as alkali metal hydroxides, one or more kinds of LiNO3, NaNO3 KNO3 are used as alkali metal nitrates and one or more kinds of LiNO2, NaNO2, KNO2, are used as alkali metal nitrites. The alloy is dipped in the fused salt containing a single compd. or two or more compds. of these. Thus, the alloy surface is effectively activated, and on which good nitridation and soft nitridation can be performed.
Inventors:
Yutaka Sawano
Hiroyuki Tomita
Hiroyuki Tomita
Application Number:
JP2743494A
Publication Date:
July 15, 2002
Filing Date:
January 31, 1994
Export Citation:
Assignee:
Parker Heat Treatment Industry Co., Ltd.
International Classes:
C23C8/02; C23C8/24; C23C8/26; (IPC1-7): C23C8/02; C23C8/24; C23C8/26
Domestic Patent References:
| JP4193963A | ||||
| JP3267380A | ||||
| JP5044934A |
Attorney, Agent or Firm:
Katsuhiro Yoshida (3 outside)
Previous Patent: MICROWAVE SEMICONDUCTOR DEVICE
Next Patent: MANUFACTURE OF INORGANIC-ORGANIC COMPOSITE MATERIAL COATED STEEL PLATE
Next Patent: MANUFACTURE OF INORGANIC-ORGANIC COMPOSITE MATERIAL COATED STEEL PLATE