Production of forgings, besides must ensure that the required shape and size, also must satisfy the performance requirements of the parts in the process of using the proposed, which mainly includes: index, plasticity index, impact toughness and fatigue strength toughness and resistance to stress corrosion resistance requirements, for the work of high temperature parts, and high temperature tensile properties of instantaneous and durable performance, creep resistance and thermal fatigue performance, etc. The performance of large forgings depends on its organization and structure (hereinafter referred to as organization).
Different materials, or different states of the same material forgings, their performance is different, in the final analysis is determined by its organization. The structure of metal is related to the chemical composition of the material, smelting method, pressure processing process and technology. The pressure process has important influence on the organization of the forgings, especially for those with no element in the process of heating and cooling heterogeneous materials, such as: austenitic and ferritic heat-resistant stainless steel, high temperature alloy, aluminum alloy and magnesium alloy, etc., mainly rely on in the process of pressure, correct control of thermodynamics process parameters to improve the forging of the organization and improve its performance.
By using the pressure machining method, the surface state of the parts can be improved and the surface precompression stress can be established to improve the performance of the parts. Because the quality of forgings is related to the quality of raw materials, forging process and heat treatment process, so to ensure high quality forgings, must be analyzed and studied from the above several aspects. During the discussion of forging quality, it is suggested to start from the following aspects: 1. The influence of materials and forging process on forging structure and properties; 2. 2. Common defects in forging process; 3. Contents of quality inspection of large forgings and methods of quality analysis of forgings.