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General Technical Specifications for Copper Alloy Castings for Rolling Stock
1 Subject Content and Application Scope
This standard specifies the technical requirements, test methods, inspection rules, marking, etc. of copper alloy castings (hereinafter referred to as "castings").
This standard is applicable to sand mold castings and special castings (metal mold casting, continuous casting and centrifugal casting) for rolling stock (including rail cranes). Special requirements (if any) shall be indicated in drawing or technical document.
2 Normative References
GB 1176 Specification for Cast Copper Alloys
GB 6414 Dimensional Tolerances for Castings
GB 6060.1 Roughness Comparison Specimens - Cast Surfaces
GB 5122.1~20 Methods for Chemical Analysis of Brass
GB 8002.1~15 Methods for Chemical Analysis of Tin Bronze
GB 5678 Sampling Methods of Spectrochemical Analysis for Cast Alloys
GB 6397 Metallic Materials - Test Pieces for Tensile Testing
GB 228 Tensile Test Method for Metal
GB 231 Metallic Materials - Brinell Hardness Test
GB/T 11350 Machining Allowances on Castings
GB/T 11351 Mass Tolerances for Castings
JB/T 5105 Casting Form Pattern Draft
GB 961 Chemical Analysis Method of High Manganese Aluminum Bronze for Propeller
YB 55 Methods for Chemical Analysis of Aluminum Bronze
3 Technical Requirements
3.1 The designation, casting method, chemical composition and mechanical performance of castings shall be selected according to the requirements of GB 1176. Common designations of castings shall meet the requirements of Annex A.
3.2 Classification (Table 1) shall be indicated in product drawing, and the unindicated castings shall be treated as Class III.
3.3 Label to be indicated in casting drawing
Label example: ZCuSn5Pb5Zn5I-Li
3.4 Sand burning, sand inclusion and metallic projections on castings shall be eliminated; residual casting heads not affecting processing, assembling and use shall meet the requirements of Table 2, and that on non-machined surface shall be smoothly transited to casting surface.
Table 1
Class Definition Inspection item Classification example
I Important castings that bear heavy load, are used in key positions under complicated working conditions or provided with special requirements, and, if damaged, will endanger the safe operation of complete machine. Chemical composition and mechanical performance Rocking or connecting rod, bell crank and copper sheath of steam locomotive. Axle suspension bush of traction motor of diesel electric locomotive. Diaphragm valve bush, spherical joint, etc. of passenger/goods locomotive
II Castings that bear medium load, are provided with high corrosion resistance, abrasion resistance or used in important positions, and, if damaged, will endanger the normal operation of components Chemical composition and mechanical performance Connecting rod brass, stop valve and injector of steam locomotive; check valve of diesel locomotive; holder of electric locomotive; tee valves and main pistons of passenger/goods locomotive
III Castings that bear light load and used in general positions Chemical composition or mechanical performance Main valve seat and rectangular valve deck of steam tower of steam locomotive. oil cylinder and valve of oil pump motor of diesel locomotive; bearing bush and spring case of electric locomotive; cock and brake shoe mounting base and valve core of passenger locomotive
3.5 Castings may be calibrated at room temperature.
Table 2
mm
Maximum dimension of casting ≤600 >600~1200 >1200
Residual quantity Machined surface ≤5 ≤10 ≤12
Non-machined surface ≤2
3.6 Where not specified in the drawing,
a. The dimensional tolerance and mismatch value of castings shall meet the requirements of GB 6414;
b. Refer to JB/T 5105 for the pattern draft requirements of castings;
c. Curving radius of castings shall be 3~8mm;
d. The surface roughness of castings shall meet the requirements of GB 6060.1;
e. The machining allowance of castings shall meet the requirements of GB/T 11350.
3.7 Where specified in the drawing, the mass tolerances of castings shall meet the requirements of GB/T 11351.
3.8 Where not specified in product drawing or technical document, defects within the range specified in this standard are permissible on casting surface.
3.8.1 Defects within the range of machining allowance are permissible on machined surface.
3.8.2 Hole defects
a. For single hole, the depth is not greater than 1/3 of the wall thickness at this position (not greater than 1.5mm on machined surface while not greater than 2.5mm on non-machined surface; not greater than 1/4 of the wall thickness at the installation edge), and the quantity is not greater than 2 within 100cm2 (the area less than 100cm2 is calculated as 100cm2); the quantity of holes with diameter not greater than 1.5mm and depth not greater than 1mm is not greater than 3 on machined surface.
b. For group holes (including pinhole, shrinkage and looseness), the depth is not greater than 1/3 of the wall thickness at this position (not greater than 1mm and 1.5mm respectively on Grade I or II machined surface and Grade III machined surface while not greater than 1.5mm and 2.0mm respectively on Grade I or II non-machined surface and Grade III non-machined surface), and the quantity (of a group) is not greater than 3 within 10cm2;
The spacing between above-mentioned defects (defect groups) is not less than 20mm, and their distance from edge or hole edge is not less than two times of the maximum hole diameter. On non-machined surface, the hole diameter and depth are not greater than 1mm; on machined surface, holes with diameter less than 0.5mm and depth less than 1mm may be ignored.
c. The diameter and total quantity of holes on each casting shall meet the requirements of Table 3.
d. Defect in the opposite position relative to the existing defect is not permissible.
1 Subject Content and Application Scope
2 Normative References
3 Technical Requirements
4 Test Methods and Inspection Rules
5 Marking
6 Packaging and Transportation
Annex A (Supplementary) Designation, Chemical Composition and Mechanical Performance of Common Cast Copper Alloys
Additional Explanation
