1. Casting
Casting is not allowed to have hole, sand holes, pinhole, osteoporosis, cold insulation, casting defects such as cracks, porosity and penetrability and severe disability defects (e.g., owe casting, mechanical damage, etc.). Castings shall be clean, can not have burr, flash, the processing that poured riser on casting surface should be clean and flush. Casting the processing on the surface of a type and marking shall be legible, position and font should comply with the design requirements. Casting processing surface roughness, sand mold casting R, not more than 50 microns. Castings poured riser shall be removed and stab fly, etc. The processing on the surface of the water the riser residual amount to wipe, polishing, meet the requirements of surface quality. On the casting sand and core sand and core bone should be cleared away. Casting has tilted parts and its dimension tolerance zone should be symmetrical configuration along the inclined plane. On the casting sand and core sand, core bones and meat more, such as adhering sand should be relief grinding smooth, clean up. Rightly or wrongly, convex platform should be corrected, such as casting partial to smooth the transition, the guarantee the appearance quality. Folds of the machining surface of castings, depth is less than 2 mm, spacing should be greater than 100 mm. The machining surface of a casting machinery products must be shot peening treatment or drum, achieve cleanliness Sa2 1/2 level requirements. The casting must be water toughening treatment. Casting surface should be smooth, gate, burr, such as adhering sand should be cleared away. Casting is not allowed to exist beneath the cold insulation used, cracks, holes and other casting defects. Symmetry in rough casting casting tolerance zone basic size configuration. Note the radius R.
2. The weldment
Before the repair welding defects must be thoroughly cleared, groove surface shall be smooth sleek, sharp corners must not exist. According to the casting defects, repair welding defects can use digging, grinding, carbon arc air gouging, gas cutting or machining methods such as cleared. Repair welding area and groove around 20 mm within the adhering sand, oil, water, rust and other dirt must be thoroughly clean. In the whole process of repair welding, steel preheating zone temperature shall not be lower than 350 ° C. In the conditions allow, as far as possible in a horizontal position welding. Repair welding, the electrode should not do too much lateral swing. Steel heap welding on the surface, the overlap between the weld bead amount shall not be less than 1/3 of the weld bead width.
Each ingot of nozzle, riser should be sufficient removal, to ensure that the forgings without shrinkage and bending. Forgings shall have enough ability to forging machine forging forming, in order to ensure the internal fully forging forgings. Forgings there is no visible cracks, folds and other effects using the appearance of the defect. Local defect can be removed, but clean up depth shall not exceed 75% of the machining allowance, forging the defects of the processing surface should be clean and smooth transition. Forgings are not allowed to exist the white dots, internal cracks and residual porosity.
4. Paint
All the need for coating of steel surface before painting, must be rust, scale, grease, dust, dirt, salt and dirt removed. Before cleaning with organic solvent, alkali, emulsifier, such as steam to remove oil and dirt on the surface of the steel parts. After the shot peening or manual derusting stay with primer coating surface of not more than 6 h time interval. Riveting pieces of mutual contact surface, in front of the connection must be for 30 to 40 microns antirust paint coating thickness. Overlapping edges used paint, putty or bonding agent. Due to the machining or welding damage of the primer, coating again. Prefabricated pipe welding parts of the complete to withstand voltage test. Piping to replace or transshipment, must separate the pipe mouth sealed with tape or plastic pipe wall, prevent into the sundries, and tied to the label.
5. Machined parts
Parts are not allowed to have burrs, parts processing on the surface, there should be no damage on the surface of the parts defects such as scratches and bruises.. After finishing the parts may not be directly on the ground, when putting the necessary support, protection measures should be taken. Machined surface are not allowed to have rust and knock against, scratches and other defects. After finishing the surface of the rolling, rolling can not have desquamate phenomenon. The final process of parts after heat treatment, surface should not have scale. After finishing the matching surface, there should be no annealing, blue, color of the tooth surface phenomenon. Processing of the surface of the screw thread are not allowed to have defects such as black, knock against, disorderly buckle and burr. Did not note the shape tolerance should accord with the requirement of GB1184-80.
6. Assembly
The seal must be soaked with oil before assembly. Assembly of hot charging rolling bearings allow used engine oil heating, oil temperature shall not exceed 100 ℃. After gear box assembly shall, in accordance with the provisions of design and process for no-load test. Test should not be shock, noise, temperature rise and leakage shall not exceed the prescribed standards. After gear assembly, the tooth surface contact spots and clearance shall comply with the terms of GB10095 and GB11365. When assembling hydraulic system allows the use of packing or sealant, but should prevent into the system. Enter the assembly of parts and components (including purchased parts and outsourcing parts), all must have the certificate of inspection departments can undertake assembly. Parts must be clean before assembly and clean, no burr, flash, scale, rust, chip, oil, stain and dirt, etc. Before assembly to the main dimension zero, components, especially interference fit the size and the related accuracy for review. Parts are not allowed to knock, touch in the process of assembly, scratches and corrosion. Screws, bolts and nuts tightened, it is forbidden to hit or use of unsuitable whorls and wrench. After fastening screw groove, nut and screw, bolt head is allowed to damage. Tightening torque requirements of fasteners, torque wrench must be used, and in accordance with the provisions of torque to tighten. Tightening torque requirements of fasteners, torque wrench must be used, and in accordance with the provisions of torque to tighten. The same parts with more than (bolt) fastening screw, the screw bolts () to cross, symmetry, step by step, and even tighten. Taper pin assembly should be checked and the hole should be painted, when its rate should not be less than 60% with the length of contact, and should be evenly distributed. Flat key contact with shaft keyway on the two sides should be uniform, the matching surface can not have clearance. Spline fitting and contact number of tooth surface of not less than two-thirds, contact rate at key tooth length and height of the direction shall not be less than 50%. Sliding fit flat key (or spline) after the assembly, parts move freely, can not have slack phenomenon of adhesive should be cleared out excess adhesive. After. Bearing outer ring and the open type bearing and the bearing cover of the round hole is allowed to have stuck phenomenon. Bearing outer ring and the open type bearing and the bearing cover of semicircle holes should be good contact, use color to check, and bearing in the symmetry in the center line of 120 °, 90 ° with bearing cover in symmetry in the centerline of the range should be uniform. When using a feeler check in the above scope, 0.03 mm feeler into 1/3 of the width of the outer ring is not allowed. Bearing outer ring assembly after contact with the positioning end bearing cover face should be smooth. Rolling bearing installed by hand rotation should be flexible, and stable. The combination of upper and lower bearing surface to tightly stick and, with a 0.05 mm feeler check not into. With dowel bearing shell, should be in guarantee WaKou surface and end face and the related bearing hole opening and closing and end of bread leveled state under a hinge, distribution. After the pin into the shall not be loose. Spherical bearing of the bearing body contact with the bearing should be uniform, check with painting method, and it should not be less than 70%. Are not allowed to be used when the yellow metal bearing liner surface, within the prescribed contact Angle are not allowed to have nuclear phenomena, outside contact Angle away from the nuclear area shall not be greater than the contact zone with a total area of 10%. Gear (worm) reference face and shoulder (or locating sleeve ends) should be nicely, with 0.05 mm feeler check not into. And shall ensure that the reference face gear and the axis of vertical degree requirements. The combination of gear box and cover surface should be in good contact. Strict inspection before assembly and removal of parts processing residues of acute Angle, burr and foreign body. Keep the seal loads from scratch.
