GB/T 38884-2020 English PDF (GBT38884-2020)

This standard specifies the classification and code, order content, size, shape, weight, technical requirements, test methods, inspection rules, packaging, markings and quality certificates of high temperature stainless steels for bearing. This standard applies to hot-rolled or forged round steel, cold-drawn round steel and steel wire for the manufacture of stainless steel bearings that can withstand high temperatures of 300 ~ 400 degree-Celsius.

GB/T 38884-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.10
H 40
High temperature stainless steels for bearing
ISSUED ON: JUNE 02, 2020
IMPLEMENTED ON: DECEMBER 01, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Classification and code ... 6
4 Order content ... 7
5 Dimensions, appearance and weight ... 7
6 Technical requirements ... 8
7 Test method ... 13
8 Inspection rules ... 14
9 Packaging, marking and quality certificate ... 15
Appendix A (Informative) Comparison of designations between this standard, old designations, foreign designations ... 16
High temperature stainless steels for bearing
1 Scope
This standard specifies the classification and code, order content, size, shape, weight, technical requirements, test methods, inspection rules, packaging, markings and quality certificates of high temperature stainless steels for bearing. This standard applies to hot-rolled or forged round steel, cold-drawn round steel and steel wire (hereinafter referred to as steel) for the manufacture of stainless steel bearings that can withstand high temperatures of 300 °C ~ 400 °C. 2 Normative references
The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this standard.
GB/T 222 Permissible tolerances for chemical composition of steel products GB/T 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method
GB/T 223.11 Iron, steel and alloy - Determination of chromium content - Visual titration or potentiometric titration method
GB/T 223.13 Methods for chemical analysis of iron, steel and alloy - The ammonium ferrous sulfate titration method for the determination of vanadium content
GB/T 223.23 Iron, steel and alloy - Determination of nickel content - The dimethylglyoxime spectrophotometric method
GB/T 223.26 Iron, steel and alloy - Determination of molybdenum content - The thiocyanate spectrophotometric method
GB/T 223.53 Methods for chemical analysis of iron, steel and alloy - The flame atomic absorption spectrophotometric method for the determination of copper content
GB/T 223.62 Methods for chemical analysis of iron, steel and alloy - The tower sample
GB/T 10561-2005 Steel - Determination of content of nonmetallic inclusions - Micrographic method using standards diagrams
GB/T 11170 Stainless steel - Determination of multi-element contents -
Spark discharge atomic emission spectrometric method (Routine method)
GB/T 13298 Inspection methods of microstructure for metals
GB/T 14979-1994 Eutectic carbide of steel - Micrographic method using
Standard diagrams
GB/T 15711 Inspection of non-metallic inclusions of steel - Etching test method of tower samples
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content Infrared absorption method after combustion in an induction furnace (routine method)
GB/T 32548 Determination of iron, tin, antimony, cerium, lead and bismuth - Inductively coupled plasma - mass spectrometric method
GB/T 36026-2018 High-strength corrosion-resistant alloy bars for oil and gas engineering
YB/T 4395 Steel - Determination of molybdenum, niobium and tungsten
contents - Inductively coupled plasma atomic emission spectrometric
method
YB/T 4396 Stainless steel - Determination of multi-element contents -
Inductively coupled plasma atomic emission spectrometric method
3 Classification and code
3.1 Steels are divided into the following two categories according to the processing methods used:
a) Steel for pressure processing UP;
b) Steel for cutting UC.
3.2 Steels are divided into the following two categories according to their end use:
6.12.2 The total decarburization depth on each side of the cold-drawn round steel and steel wire surface shall not be greater than 1.5% of the nominal diameter.
6.12.3 There shall be no decarburized layer on the surface of the stripped and polished steel.
6.13 Ultrasonic testing
The steel shall be subjected to ultrasonic testing according to GB/T 4162-2008 one by one. It shall meet the requirements of Class A.
6.14 Surface quality
6.14.1 The surface of hot-rolled (forged) round steel shall not have cracks, folds, tears, scars, inclusions or other defects harmful to use; it shall meet the following requirements:
a) For the removal depth of harmful defects on the surface of steel for pressure processing from the actual size, it shall not exceed half of the dimensional tolerance for the round steel with a nominal diameter of less than 80 mm; it shall not exceed the dimensional tolerance for the round steel with a nominal diameter of more than 80 mm;
b) For the removal depth of harmful defects on the surface of steel for cutting processing from the actual size, it shall not exceed half of the dimensional tolerance for the round steel with a nominal diameter of less than 80 mm; it shall not exceed the dimensional tolerance for the round steel with a nominal diameter of more than 80 mm.
6.14.2 The surface of cold-drawn round steel shall be clean and smooth; there shall be no harmful defects such as cracks, scars, folds, rust and oxide skin. The surface is allowed to have pitting, scratches, pull marks, dark spots, concave surfaces, cleaning oblique marks, lubricant marks and individual small hairlines whose depth does not exceed half of the dimensional tolerance from the actual size.
6.14.3 There shall be no flaws, such as cracks, folds, scars, etc., on the surface of the steel wire. Individual mechanical scratches and pits are allowed. The