This standard specifies the method for evaluating the surface roughness of castings. This standard is applicable to the evaluation of the casting surface roughness of castings using the casting surface roughness comparison sample block specified in GB 6060.1. This standard is not applicable to the evaluation of the residual surface of gates, risers, and patches. Casting surface defects (such as sand sticking, scarring, etc.) are not included in the inspection surface. GB/T 15056-1994 Method for evaluating the surface roughness of castings GB/T15056-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Evaluation method on cast surface roughnessbzxz.net
Evaluation method on cast surface roughness 1 Subject content and scope of application
This standard specifies the evaluation method on cast surface roughness. GB/T15056
This standard applies to the assessment of the casting surface roughness of castings using the casting surface roughness comparison sample specified in GB6060.1.
This standard does not apply to the assessment of the residual surface of pouring, bubbling and patching. Casting surface defects (such as sand sticking, scarring, etc.) are not included in the inspected surface.
2 Reference standards
GB6060.1 Surface roughness comparison sample casting surface 3 Casting surface roughness parameter value grade
The casting surface roughness parameter value grade shall comply with the provisions of Table 1 of GB6060.1. 4 Comparison method of casting surface roughness comparison sample 4.1 Using the casting surface roughness comparison sample specified in GB6060.1, the casting surface of the inspected casting shall be compared by visual or tactile methods.
4.2 The casting alloy material and process method should be selected to match the casting alloy material and process method. 4.3 The surface of the casting to be inspected must be cleaned, and there must be no oil or rust on the surface of the sample block and the surface of the casting to be inspected. 4.4 Visual comparison should be made with eyes under sufficient light, or with a magnifying glass. 4.5 When making a tactile comparison, use your fingers to touch the surface of the casting to be inspected and the surface of the sample block with two similar parameter value levels. The level that gives the same feeling is the surface roughness value of the casting to be inspected. 5 Evaluation of casting surface roughness parameter value level 5.1 The casting surface to be inspected is evenly divided into ten test units, and the test units are compared one by one with the sample block. 5.2 The number of divided test units must comply with the regulations in the following table. The area of ​​each test unit shall not be less than the area of ​​the sample block. Area of ​​the casting surface to be inspected.cm2
Number of test units
200～1000
Not less than 5
1000～10 000
Not less than 10
10 000
Not less than 20
5.3 The surface roughness parameter value level of the test unit shall be evaluated based on the level with the largest surface roughness parameter value within the surface. When the surface roughness is between the two parameter values ​​of the comparison sample, the level with the larger value shall be evaluated. 5.4 Arrange the surface roughness parameter values ​​of all test units from small to large, and select the level with the largest value from the lowest level. Approved by the State Administration of Technical Supervision on May 3, 1994 and implemented on March 1, 1995
GB/T 15056—94
The maximum parameter value level is determined as the surface roughness level of the casting, but the surface roughness parameter value level of the remaining 20% ​​of the test units shall not be greater than the set level by more than...levels! . 5.5 When the surface roughness level of 20% of the test units is one or two levels higher than the surface roughness level of 80% of the test units, the smaller level of the maximum parameter value of these 20% of the test units is determined as the surface roughness level of the tested casting. 5.6 When the area of ​​the tested casting surface is less than 200cm2, the surface roughness level with the largest parameter value of the tested casting surface shall be used for evaluation. 5.7 When the casting surface roughness is coarser than the specified level, it can be refined. After refinement, it can be tested with reference to the casting surface roughness comparison sample block. 5.8 When the two parties have a dispute over the results of the evaluation with the comparison sample block and need arbitration, the roughness wheel meter shall be used for testing. 5.9 If there are special requirements, it can be agreed upon by the supply and demand parties. See Appendix A (reference) for examples of evaluating casting surface roughness
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GB/T15056---94
Appendix A
Examples of evaluating casting surface roughness parameter grades (reference)
Example 1: If the casting surface to be inspected is divided into 10 inspection units, the maximum parameter value grades of each inspection unit are: R.25; R25; R.12.5R25; R.12.5; R25; R50; R12.5; R.25; R50. Among them, there are 2 R.50, 5 R.25, and 3 R12.5. If the parameter values ​​in 80% of the inspection units are R.12.5; R.25, then the maximum parameter value grade is R.25; if the parameter values ​​in 20% of the inspection units are R.50, then the maximum parameter value grade is R.50. Then the roughness grade of the inspected casting surface should be set as R,25. Example 2: If the casting surface to be inspected is divided into 10 inspection units, the maximum parameter value level of each inspection unit is: R.25; R.25; R.50; R.50: R.12.5; R.50; R25; R12.5; R25; R25. Among them, there are 3 R.50, 5 R25, and 2 R12.5. If the parameter values ​​in 80% of the inspection units are R12.5; R.25; R.50, then the maximum parameter value level is R, 50; if the parameter value in 20% of the inspection units is R.50, then the maximum parameter value level is R.50. Then the surface roughness grade of the tested casting should be R.50. Example 3: If the tested casting surface is composed of 10 test units, the maximum parameter value grade of each test unit is: R.25: R.25: R, 50; R.25R.100; R.12.5; R.25; R12.5; R12.5; R.25. There are 1 R.100; 1 R50; 5 R25; 3 R.12.5. 80% of the test units have parameter values ​​of R.12.5; R.25, then the maximum parameter value grade is R.25; 20% of the test units have parameter values ​​of R, 50; R.100. Then the maximum parameter value grade is R.100. According to the regulations, the lower level of the maximum parameter value grade of 20% of the test units is set as the roughness grade of the tested casting, then the surface roughness grade should be set as R.50.
Additional Notes:
This standard was proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of Shenyang Foundry Research Institute of the Ministry of Machinery Industry. This standard was drafted by Harbin Institute of Science and Technology. The main drafters of this standard are Ren Shanzhi, Li Anmin, Jin Jingning, Chen Hetao and Chen Jie.
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