There are many machining methods for machining, and the types of machining workpieces are also various. Different kinds of workpieces have different machining methods, and different kinds of workpieces also have different machining technical requirements. The following Yuntuo machining and everyone What are the conventional technical requirements for machining of various workpieces?

1. Conventional technical requirements for machining of castings

1. Cold partitions, cracks, shrinkage cavities, penetrating defects and serious incomplete defects (such as under-casting, mechanical damage, etc.) are not allowed on the surface of the casting.

2. The castings should be cleaned without burrs or flashes. The pouring risers on the non-processing surface should be cleaned and flush with the surface of the castings.

3. The cast characters and signs on the non-machined surface of the castings should be clearly identifiable, and the positions and fonts should meet the requirements of the drawings.

4. The roughness of the non-machined surface of the casting, sand casting R, is not more than 50μm.

5. Castings should be clear of pouring risers, flying spurs, etc. The residual amount of the pouring riser on the non-machined surface should be leveled and polished to meet the surface quality requirements.

6. The molding sand, core sand and core bone on the casting should be cleaned.

7. The casting has inclined parts, and its dimensional tolerance zone should be symmetrically arranged along the inclined plane.

8. The molding sand, core sand, core bone, succulent, sticky sand, etc. on the casting should be smoothed and cleaned.

9. Correction of the wrong type and cast deviation of the boss should be corrected to achieve a smooth transition and ensure the appearance quality.

10. For the wrinkles on the non-machined surface of the casting, the depth is less than 2mm, and the spacing should be greater than 100mm.

11. The non-machined surfaces of machine product castings shall be shot peened or roller treated to meet the requirements of cleanliness Sa2 1/2.

12. Castings must be water toughened.

13. The surface of the casting should be flat, and the gate, burr, sticky sand, etc. should be cleaned.

14. Castings are not allowed to have casting defects such as cold partitions, cracks, and holes that are detrimental to the use.

2. Conventional technical requirements for machining of forgings

1. The nozzles and risers of the forgings should have enough cutoff to ensure that the forgings have no shrinkage holes and serious deflection.

2. The forging should be forged on a forging press with sufficient capacity to ensure that the interior of the forging is fully forged.

3. Forgings are not allowed to have visible cracks, folds and other appearance defects that affect the use. Local defects can be removed, but the cleaning depth should not exceed 75% of the machining allowance. Defects on the non-machined surface of the forging should be cleaned up and smoothly transitioned.

4. Forgings are not allowed to have white spots, internal cracks and residual shrinkage holes.

3. Conventional technical requirements for welding parts machining

1. The defects must be completely removed before welding, the groove surface should be smooth and smooth, and there should be no sharp corners.

2. The defect area of ​​the weldment can be removed by shovel excavation, grinding, carbon arc gouging, gas cutting or mechanical processing.

3. Dirt such as sticky sand, oil, water, rust and other dirt within 20mm around the welding area and the groove must be thoroughly cleaned.

4. During the whole process of welding, the temperature of the preheating zone shall not be lower than 350°C.

5. When conditions permit, apply welding in a horizontal position as much as possible.

6. During repair welding, the electrode should not swing too much laterally.

7. During surface surfacing welding, the overlap between the weld bead shall not be less than 1/3 of the width of the weld bead. The welding meat is full, and the welding surface is free of burns, cracks and obvious nodules.

8. The appearance of the welding seam is beautiful, and there are no defects such as bite, slag, pores, cracks, splashes, etc.; the welding wave is uniform.

4. Conventional technical requirements for machining of cutting parts

1. Parts should be inspected and accepted according to the processing procedure, and only after passing the inspection of the previous procedure can they be transferred to the next procedure.

2. The processed parts are not allowed to have burrs.

3. The finished parts should not be placed directly on the ground, and necessary support and protection measures should be taken. The machined surface is not allowed to have rust, bumps, scratches and other defects that affect performance, life or appearance.

4. The surface of rolling finishing should not have peeling phenomenon after rolling.

5. There should be no oxide scale on the surface of the parts after heat treatment in the final process. Finished mating surfaces and tooth surfaces should not be annealed

6. The surface of the processed thread is not allowed to have defects such as black skin, bumps, random buckles and burrs.

Different workpieces will have different technical requirements for machining. We can only perform machining in accordance with conventional technical requirements, so as to better ensure the quality of workpieces.