21.100.20 Standard of the Machinery Industry of the People's Republic of China JR/T9145-1999 Hard Metal Balls Published on 1999-06-28 National Bureau of Machinery Industry Implemented on 2000-01-01 JB/T9145—1999 This standard is a revision of 78J11017—9 "Hard Metal Balls". This standard mainly makes editorial modifications or supplements to the writing format and some articles. This standard replaces ZBJ11017—89 from the date of implementation. This standard is proposed and managed by the National Standardization Technical Committee for Transverse Dynamic Bearings. The drafting unit of this standard is Luoyang Bearing Research Institute. The main authors of this standard are Zhang Yongchu, Xu Zhongxing, Sun Yongan, Gu Xiquan and Xiang Wenbao. This standard was first issued in 198. Standard of the Machinery Industry of the People's Republic of China Hard alloy balls Hard inclul bells The standard specifies the size and technical policy of various grades of hard alloy balls. JB/T9145—1999 Replaces J1017-89 This standard applies to the manufacture, inspection and acceptance of hard alloy balls for instrument probes, special bearings and other purposes. 2 Reference Standards The provisions contained in the underlined standards constitute the provisions of this standard through their use in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the newer versions of the following standards: GB.T398--1989 GD/T 1R17-- -1979 GD/T 3488—1981 GT3489—1983 GB/T3849—1983 GBT3850—1983 GB/T 38511983 GB/ 5242-1985 GB/T6430—1986 JB/T 3034.—1993 IB/T 705[—1993 JR/892[—1999 YS/T 400—1994 3 Technical specifications, special numbers and explanations Rolling bearing balls Test method for hot impact toughness of cemented carbideMetallographic determination of microstructure of cemented carbide Metallographic determination of porosity and uncombined carbon in cemented carbideMethod for determination of hardness (A scale) of sintered alloys and cemented carbideMethod for determination of transverse fracture resistance of cemented carbideMethod for inspection and test of cemented carbide productsVocabulary for rolling bearings Rust-proof packaging for rolling bearings Measurement of torsion modulus of rolling bearing parts and the force methodInspection rules for rolling bearings and their product partsCemented carbide enterprise grades The following terms are not defined herewith, and their definitions and explanations are specified in G693. 3.1 Nominal diameter of ball Dw 3.2 Single diameter of ball Dw 3.3 Average diameter of ball Dwr 3.4 Variation of ball diameter V.. 3.5 Spherical reading error 45%. Approved by State Machinery Industry Bureau on 1999-06-28 and implemented on 2000-01-01 3.# Batch average diameter Dwalbzxz.net 3.8 Batch diameter variation Fpm 3.9 Ball tolerance grade JB/T9145—1999 3.10 Batch half-average diameter deviation: the difference between batch average diameter and nominal diameter of ball: 3.11 Under-firing: the sintering temperature of the product is too low and the sintering time is too long, so that the product does not meet the required sintering performance. 3.12 Delamination: The defect of the product in the process of deterioration or sintering is a typical defect. 3.13 Cracks: Irregular interfaces and cracks that are not visible on the surface, corners and parts of the product. 3.14 Dirt: Tiny holes or inclusions that can be observed under a low-power microscope on the cross section of the product. 3.15 Porosity: The ratio of the volume of the pores in the product to the total volume. 3.16 Uncombined carbon: The granules in the structure of cemented carbide are called uncombined carbon. 3.17 Degree of dirt: Under the metallographic microscope with a magnification of 100-110 times, the holes with a size of or greater than 50 μm and clear edges are called pits. The total length (micrometers) of all dirt folds per square meter of grinding wheel is called the degree of dirt. 3.18 Holes: Micropores with a certain depth that are visible on the surface of the product. 3.19 Pits: Small pits with a small visible bottom on the surface of the cemented carbide ball. 4 Size Nominal diameter of cemented carbide balls, see Table 1. Table 1 Nominal diameter D of balls Note: When requesting a cemented carbide ball with a specified diameter in the supply table, the order can be determined through negotiation between the subscriber and the manufacturer. 5 Technical requirements 5. Tolerance grade of cemented carbide balls Cemented carbide balls are divided into five grades: 5, 10, 16, 40, and 100, with the accuracy from high to low. 5.2 Shape tolerance of cemented carbide balls of each grade: batch diameter variation and applicable size range 5.2.1 The shape tolerance and surface roughness of cemented carbide balls, batch diameter variation, shall be in accordance with the provisions of Table 2. 232 Ball point diameter variation chart JB9145-1999 Ball shape Bone surface The diameter tolerance of each grade of balls and the applicable size pool shall comply with the provisions of Table 5.2.2 s.3 Appearance Blind diameter tolerance The surface of the hard alloy ball shall not have cracks and visible pits, gas and surface corrosion. 5.4 Material Point diameter arrangement Avoided size flow Tungsten hard alloy balls are made of tungsten hard alloy, and their chemical composition and physical and mechanical properties shall comply with the provisions of Table 1. If other hard alloy balls are required, the subscriber shall negotiate with the manufacturer to determine. 5.5 Dimensions 5.5.1 The dimension of hard alloy balls shall comply with the provisions of Test 4. 5.5.Z The hardness difference of each point of a single hard alloy ball should not be greater than 1HRA 5.5.3 The hardness difference of each ball in the same batch of hard alloy balls should not exceed 2HRA. Gold medal number Chemical batch number % 1: The data listed are not specified in YST409 5.6 Group structure 9145-1999 14.5~14.9 [4.5-14.9 14 0-14.4 13.0-14.2 13.4-13,7 12 9-13.2 Physical and mechanical properties Strength version The cross section of the hard alloy ball shall not be underburned! Ink core, pores, delamination, cracks, poor pressing, severe decarburization, carbon and severe dirt 5.6.1 Chemical, The general requirements for the porosity, contamination and uncombined carbon of cemented carbide balls shall comply with the provisions of Table 5. Table 5 Cultivation station original Porosity [Volume: Tri-combined alcohol (Volume For cemented carbide balls with special technical requirements, the subscriber can negotiate with the manufacturer to determine the 6 Measuring method 6.1 Size and shape tolerance The size and shape tolerance of cemented carbide balls shall be determined according to 6DT3%B. 6.2 Torsion The measurement and evaluation of the surface roughness of cemented carbide balls shall be in accordance with the provisions of IE/T 1051. 6.3 Appearance The external quality of cemented carbide rings is generally inspected by naked eyes under a shielded light. 6.4 Physical and mechanical properties, group structure 6.4.1 Hardness inspection shall be carried out according to the method specified in 0B/T3849. 6.4.2 The low-power structure of the fracture shall be inspected with a 20-30 times magnifying glass, 2(k JB/T9145-1999 6.4.3 Metallographic inspection shall be carried out according to G 6.4.4 Density measurement shall be carried out according to the force method specified in GB/T3850. 6.4.5 Inspection of pore barrier, uncombined carbon and dirt shall be carried out according to the method specified in GB/T1817. 6.4.7 Inspection of bending resistance shall be carried out according to the method specified in GB/T3851. The inspection requirements are as follows: 1. The finished carbide balls shall be inspected by the quality inspection management department of the manufacturer. The carbide balls submitted to the subscribers shall have a quality certificate. 7.2 The AQL of the size and shape tolerance of the carbide balls shall be 0.65 respectively. Its inspection rules follow the provisions of JB/T8921, 7.3 The inspection of the physical and mechanical properties of cemented carbide balls shall be in accordance with the provisions of GB 5242. & Marking, packaging and storage of cemented carbide balls 8.1 Marking 8.1.1 Contents and order of cemented carbide ball marking The marking of cemented carbide balls is indicated by the following order. This standard number This standard number Supplementary technical service number Batch average diameter deviation or batch diameter variation number (not included) Batch average diameter deviation is indicated by a positive or negative sign. The unit "m" is not marked The grade of cemented carbide balls is indicated by a symbol G or a number. The nominal diameter of cemented carbide balls is indicated by a unit "mm\ This standard 8.1.2 Marking examples Example 1: The material is Y08 cemented carbide, the nominal diameter is 14mm, the integral number is 10, the batch average diameter deviation is +5μm, and the batch diameter variation is provided in groups. The marking is: Y14 G10+5JB/T 9145—1999 Example 2: The material is YGB cemented carbide, with a nominal diameter of 28mm and a tolerance of 40. It is not provided in groups according to the batch diameter variation, and is marked as: Y2G40bJB/T9145—1999 8.2 Packaging B.1.1 The cemented carbide balls supplied to subscribers shall be packed for rust prevention in accordance with the provisions of JBT3034. When packing, cemented carbide balls of different sizes, grades and materials shall be packed in different containers (boxes) and shall not be mixed. 8.2.2 The outside of the container (tray) for cemented carbide balls shall be marked with the number, material, mark of the cemented carbide balls, production number, manufacturer name and year and month of production. 8.3 Storage After being packed for rust prevention, cemented carbide balls shall be stored in a warehouse with a dry surface of more than 100% air circulation. Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.