GB/T 4462-1984 Rating chart for large carbides in high speed tool steel

GB/T 4462-1984 High-speed tool steel bulk carbide rating chart GB/T4462-1984 standard download decompression password: www.bzxz.net

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.
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,bzxZ.net
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.
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