What performance requirements should be met in forging production?

During the production of forgings, in addition to ensuring the required shape and size of forgings, the performance requirements of forgings during use must also be met, which mainly include: strength index, plasticity index, impact toughness, fatigue strength, initial fracture degree, stress corrosion resistance, etc. For parts working at high temperature, there are also high temperature instantaneous tensile property, endurance property, thermal denaturation resistance, thermal fatigue property, etc.

The raw materials used for forging are ingots, rolled materials, extruded materials and forging blanks. The rolled products, extruded products and forged billets are semi-finished products formed after the ingots are rolled, extruded and forged respectively. In forging production, adopting reasonable process and process parameters can improve the structure and properties of raw materials through the following aspects.

Breaking the columnar crystal, improving the macro segregation, changing the as cast structure into the forged structure, and welding the internal pores under the appropriate temperature and stress conditions to improve the density of the material; The ingot is forged to form fiber structure, and the forging is further rolled, extruded and die forged to obtain reasonable fiber direction distribution.

Control the grain size and uniformity; Improve the distribution of the second phase (such as alloy carbide in ledeburite steel); It can make the structure get deformation strengthening or deformation one by one transformation strengthening.

Due to the improvement of the above structure, the plasticity, impact toughness, fatigue strength and durability of the forgings have also been improved. Then the required hardness, strength and plasticity of the parts can be obtained through the final hot heel of the parts.

If the quality of raw materials is poor or the forging process adopted is unreasonable, forging defects may occur, including surface defects, internal defects or unqualified performance.