Forging defects classification of the two methods

A form, according to the defect classification of forging defects such as according to its form of expression to differentiate, can be divided into: external, internal and properties of three kinds of external defects such as geometry size and the shape is not in conformity with the requirements. Surface crack, folding, lack of meat, wrong. Die forging and surface pockmark, surface bubbles and orange peel shape surface, etc. This kind of defect appeared on the outer surface of the forging, it's easy to find or observed. Internal defects and can be divided into two categories, defects and microscopic defect. The former such as inside crack. Shrinkage cavity, porosity, white point, forging rhyolitic disorder, segregation, coarse grain, stone fracture, different metal inclusions, etc. ; The latter such as decarburization, carburization, banded structure. Casting organization residual and carbide segregation level does not conform to the requirements, etc. Internal defects exist in the interior of the forgings, the reason is complex, difficult to identify, often causes big difficult to production. Reflected in the performance of defects, such as room temperature strength and plasticity. Toughness and fatigue performance is unqualified; Or transient intensity, high temperature enduring strength, durable plastic, creep strength is not in conformity with the requirements, etc. Of the defects in performance only after the performance test, can know for sure. It is important to note that the internal. External defects and performance between the three, often have inalienable connection. Overheating and burning performance on the outside, for example, often in the form of crack, performed in internal to the coarse grain big or decarburization, performance in terms of performance for low plasticity and toughness. Therefore, in order to accurately determine the reason of forgings defect, besides must identify their forms and characteristics, also should pay attention to find out the internal relation between them. Second, according to the process or processes of defects, according to the classification of forging defects produced in which process to distinguish, can be divided into: raw materials, production process of flaws in the process of forging and heat treatment process of defects. In accordance with the order of the forging process of each working procedure also can be produced in the process of forging defects, subdivided into the following categories: produced by cutting defects; Produced by heating defects: produced by forging defects: defects produced by cooling and defects produced by cleaning, etc. Different processes can produce different forms of defects, however, the same kind of defect can also come from different processes. Due to the reasons of forging defects are often related to raw material production process and heat treatment after forging, so on the analysis of the causes of forging defects, not in isolation.