This standard specifies the technical requirements, inspection methods and acceptance rules for nitriding and nitrocarburizing of metal cutting machine tool parts. This standard is applicable to steel and iron parts treated by gas nitriding, ion nitriding and nitrocarburizing. JB/T 8491.5-1996 Technical conditions for heat treatment of machine tool parts Nitriding and nitrocarburizing JB/T8491.5-1996 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T8491.5—1996
Technical Conditions for Heat Treatment of Machine Tool Parts
Nitriding and Nitrocarburizing
Published on November 7, 1996
Mechanical Industry Standard of the People's Republic of China
Implementation on January 1, 1997
JB/T8491.5—1996
This standard is formulated on the basis of summarizing many years of production experience in heat treatment of machine tool parts in my country and referring to relevant foreign technical data. It is the replacement of TB/T54219—94 "General Conditions for Heat Treatment of Machine Tool Parts with Nitrogen and Nitrocarburizing". This standard is proposed by the National Technical Committee for Machine Tool Standardization. This standard is under the jurisdiction of Beijing Machine Tool Research Institute of the Ministry of Machinery Industry, and the drafting unit is Beijing Machine Tool Research Institute of the Ministry of Machinery Industry, which was first published in 1994.
Standard of the Machinery Industry of the People's Republic of China
Technical Conditions for Heat Treatment of Machine Tool Parts
Ammonia Carburizing, Ammonia Carbon Co-carburizingWww.bzxZ.net
JB/T8491.51996
Replacement IB/T42[9—94
This standard specifies the technical requirements for the calculation and nitrogen co-carburizing of the parts before cutting (hereinafter referred to as the parts), the test method and the test specification.
This standard is applicable to steel and iron parts treated with gas nitrogen reduction, ion nitrogen and nitrogen carbon co-carburizing. 2
References
The provisions contained in the following standards shall constitute the provisions of this standard by using them in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the following new versions: GB -3484
GB 4342$4
8 1135489
3 Appearance quality
Metallic electrostatic test method
Determination of air layer depth and metallographic inspection of steel parts 3.1 The surface of the parts should be natural gray or white, and there should be no defects such as shearing, bruising and electric burns. 3.2 Inspection by naked eye or low-power human observation 4 Surface hardness
After deterioration by ammonia or other means, the product should not be less than the requirements. 4.1
Weak material
2cCrMa
20C-MnTI
35CtMs
38CrtMoAiA
Q1600-3
The surface roughness of filter parts after simple carbon co-stabilization shall not be lower than that specified in Table 3. 4.2
Approved by the Ministry of Machine Tool Industry on November 7, 1996
Implementation on January 1, 1997
20CtMa
20CrMnTi
QT600-2
JB/T8491.5—1996
Chemical layer
0.D100.025
With certificate
For parts made of materials other than this standard, the hardness shall comply with the requirements of the drawings or process documents: 4.3
The hardness of the local anti-seepage part shall not affect the cutting performance and opening performance of the part. 4.4
4.5 The hardness shall be measured on the same part, and the test specimen can also be used when conditions permit. The surface strength of the hydrogen-filled parts shall be measured according to the method specified in GB4340, and the test load shall be 9.8~0RN; the surface strength of the oxygen-carbon co-existing parts shall be measured according to the method specified in GB4342. 5
The brittleness shall be evaluated according to GB4354, with 1-2 levels for main parts and 1~3 levels for non-main parts. The depth of the nitriding layer
The depth of the nitriding layer of the finished product shall comply with the assumptions in the selected process documents, and the deviation of the nitriding layer depth is shown in Table 33
The depth of the nitriding layer of the finished product shall not exceed the provisions of Table 4. 62
The depth of the nitriding layer
Note: The company's approval refers to the consistency of the nitriding layer obtained by the same processing of the same material
The same method
JRT S491.5-1996
6.3 For parts that are no longer subjected to rate cutting after nitriding, the calculated compound layer depth should not exceed 0.mm6.4 The detection depth of the healed layer should comply with the requirements of Table 2. 6.5 The detection depth of the healed layer should be measured on the same treated sample according to the method specified in GB11354. When there is a difference, the part measurement should be carried out. The amide form
chloride form should be evaluated according to GB11354. The main parts are qualified for level J~2, and the non-deformed parts are qualified for level [-3]. The carbon deposition test is carried out according to GB11354. The main parts are qualified for level 1-2, the main clean parts are qualified for level 1~3, and the deformation of the parts should comply with the requirements of the net fence or: art cow. Cold correction is not allowed. 10 Acceptance regulations
10.1 The product is qualified if it meets the relevant indicators specified in the technical requirements. 102 Appearance quality, surface hardness, depth of stable layer and deformation development are the necessary inspection items. Each piece should be inspected. The remaining inspection items and batch inspection items can be specified in the technical specifications.
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