Special technical requirements for common forgings on forging process cards or technical agreements
1, special requirements for hydraulic press forgings and free forgings
1 Chemical composition requirements: in the drawings or technical agreement on the requirements of special chemical composition, its chemical composition analysis methods can be referred to the provisions of gb/t222-1984 and gb/t223.1?72-1971?1997.
2 Cold bending test: According to the provisions of gb/t232-1999. 3 Low-magnification test: The method of detecting microstructure defect of forgings is called low magnification test. Low magnification can be examined for defects such as white spots, inclusions, segregation and cracks.
May be carried out in accordance with the provisions of gb/t226-1991 and gb/t979-1980.
4) High-power test: Inspection of forgings microstructure, grain according to gb/t6394-1986, yb25-1977 and yb28-1959 of the provisions of the test rating.
5 Ultrasonic test: Sometimes forgings require ultrasonic means to test inclusions, white dots and other internal defects, can be carried out according to the provisions of jd4009-85.
6 for pressure vessels, marine forgings, power plant forgings, etc., have special inspection items and inspection methods, should be carried out according to the specific technical requirements.
2, Die forgings common special requirements
1 Tolerance: forgings In addition to dimensional tolerances, but also requires weight tolerances, such as connecting rod forgings, weight tolerances are generally not more than 8% of the weight of the forgings calculation. 2) imprint requirements: such as part number, steel number, factory serial number, etc. according to the production volume pumping a certain number of forgings in the non-machined surface.
Sometimes forgings smaller, and the use of stamped marks, according to the number of pumping a certain amount tied to the forgings.
3 Forging on the streamline: for some impact forgings, such as cutting tools, modules and other forgings, often have a metal streamline requirements, in the forging diagram with the arrows on the streamline side to ask. 4 metallographic organization: forgings on the grain size, decarbonization layer requirements, all to be metallographic inspection.
Some stainless steel forgings also have intergranular corrosion requirements.
5 Mechanical Properties Requirements: forgings have strength, plasticity, Leng and other mechanical properties of the inspection requirements, you can refer to the "hydraulic Press free forgings general technical conditions and acceptance measures" for destructive experiments, or by batch forgings to leave certain specifications of the sample for special testing. 6 rust-proof, paint, packaging requirements: these belong to the requirements of the forging after delivery, the special technical Agreement must be specific content.