The effects of forging on the microstructure and mechanical properties of metals

In forging production, besides must ensure that the forgings to the required shape and size, also must satisfy the performance requirements of the parts in the process of using the proposed, of which mainly includes: pointer, plastic pointer strength, impact toughness, fatigue strength, fracture toughness and stress corrosion resistance, etc. , for the work of high temperature parts, and high temperature tensile properties of instantaneous and durable performance, creep resistance and thermal fatigue performance, etc. Raw materials are ingot casting, rolling, forging and forging billet. And rolling, bar and forging billet are respectively ingot are formed after rolling, extrusion and forging processing semi-finished products. Forging production, using reasonable technology and process parameters, can through the following several aspects to improve the organization and performance of raw materials: 1) Break the columnar crystal, improve macro segregation, the as-cast organization into forging state organization, and under the appropriate conditions of temperature and stress welded internal pore, improve the density of material; 2) Ingot after forging formation of fibrous tissue, further through the rolling, extrusion, die forging, forging get reasonable distribution of fiber direction; 3) Control of grain size and uniformity; 4) To improve the second phase ( For example: the alloy carbide in ledeburite steel) The distribution; 5) Make the organization get deformation strengthening or deformation - — Phase transformation strengthening, etc. Due to the improvement of the organization, forgings plasticity, impact toughness, fatigue strength and the durable performance has been improved, and then the final heat treatment of the parts can get parts required hardness, strength and good comprehensive properties such as plastic. However, if the poor quality of raw materials or forging process is not reasonable, may produce forging defects, including surface defects, internal defects or performance is unqualified, etc.