Standard ICS number:Metallurgy>>Metal Material Testing>>77.040.30 Chemical Analysis of Metal Materials
Standard Classification Number:Metallurgy>>Methods for testing physical and chemical properties of metals>>Methods for testing H23 metal processing properties
National Standard of the People's Republic of China Rating chart of bulk carbide of high speed tnol steel UDC669.14.025 GB4462-84 This rating chart is applicable to the evaluation of bulk angular carbide of hot-rolled, forged or cold-drawn tungsten high-speed tool steel and bulk granular carbide of aluminum high-speed tool steel wire. According to relevant standards or agreement between the supply and demand parties, this rating chart can also be used to evaluate bulk carbide of high-speed tool steel plates, strips and other materials. bZxz.net Bulk angular phosphide and bulk granular carbide are collectively referred to as bulk carbide. 1 Classification Rating charts are divided into two categories: First level chart: Rating chart of bulk angular carbide of aluminum high-speed tool steel. Column A National Bureau of Standards 198406-05 Issued 198506.01 Implementation GB 4462-84 GB4462-84 First level chart Tungsten series high speed tool steel large block angular carbide rating chart 500× Second level chart: Molybdenum series high-speed 1: tool wire large particle carbide rating. 1 level 2 Features GB 4462-84 First level chart Key series high speed 1 tool wire large particle short carbide rating chart 500×2.1 Tungsten series high speed tool steel large block angular carbide rating chart Column A: Dispersed series. Block angular carbides are dispersed, see column A of the first level. The maximum size of block angular carbides of each level shall comply with the provisions of Table 1. Maximum size of large angular carbides Column B: In the aggregate series, large angular carbides are concentrated, see column B of the "level chart". The maximum size of large angular carbides of each level shall comply with the provisions of Table 2. Maximum size of large amber-like carbides GB 4462-—84 2.2 Rating diagram of large carbide particles of molybdenum high-speed tool steel wire. Large carbide particles are dispersed on a uniform and fine carbide matrix, see the first level diagram. The maximum size of large carbide particles of each level shall comply with the provisions of Table 3. Maximum size of large carbide particles Test method 3.1 Large angular carbides and granular carbides are evaluated by metallographic comparison. When there is a dispute, the maximum carbide size can be determined. 3.2 When measuring the maximum carbide size, it can be calculated according to the following formula: Carbide size (μm) = α + -the maximum length of carbides in any direction (long axis size), μm: α- The maximum length of carbides perpendicular to the a direction (short axis size), μ㎡. b 3.3 The inspection of large angular carbides should be carried out on the longitudinal section at 1/4 of the diameter or diagonal of the steel sample. The most serious part in the field of view is compared with the first level diagram for evaluation. The sample thickness is 10-12mm. The sample is tempered at 680-700℃ for 1-2h after tumbling according to the heat treatment process specified in the corresponding standard. The magnification is 500 times. 3.4 The inspection of large particle carbides should be carried out on the transverse sample of the steel wire in the quenched state. The most serious part in the field of view is compared with the second level diagram for evaluation. The magnification is 500 times. a.5 The preparation of metallographic samples shall comply with the provisions of YB2859 "Method for Metal Microstructure Inspection". 4 Qualified level The qualified level of large angular carbides of tungsten high-speed steel shall comply with the provisions of Table 4 when evaluating according to the first level diagram. 4.1 The maximum size of large angular carbides in the field of view of each sample is allowed to be 4μm larger than the limit size. 4 Steel size, 13 ~ ah 80~ 120 Qualified level, not too large Both parties agree GB 4462-84 4.2 Evaluate the large particle carbides of molybdenum-based high-speed tool steel wire according to the second level diagram. For aluminum-based high-speed tool steel wire, it shall not be greater than level 4. Other steels shall be specified in the corresponding technical conditions. Additional remarks: This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by Dalian Steel, Shanghai No. 1 Iron and Steel Plant, and the Standardization Research Institute of the Ministry of Metallurgical Industry. The main drafters of this standard are He Chengxiu, Yu Lianbin, Jiang Weiyu, Xu Tianlin, and Guo Yunfu. 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.