Contents of quality inspection of hottest forgings

2022-08-22
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The content of forging quality inspection

the existence of forging defects will affect the treatment quality or processing quality of subsequent processes, and some will seriously affect the performance and use of forgings, and even greatly reduce the service life of finished products, endangering safety. Therefore, in order to ensure or improve the quality of forgings, in addition to strengthening quality control in the process of industrialization, informatization, urbanization, marketization and internationalization, and taking corresponding measures to prevent the occurrence of forging defects, necessary quality inspection should also be carried out to prevent forgings with defects that have a bad impact on subsequent processes (such as heat treatment, surface treatment, cold processing) and service performance from flowing into subsequent processes. After quality inspection, remedial measures can also be taken for the manufactured forgings according to the nature of defects and the degree of impact on use, so as to make them meet the technical standards or use requirements

therefore, in a sense, the quality inspection of forgings is to check the quality of manufactured forgings on the one hand, and point out the improvement direction for the forging process on the other hand, so as to ensure that the quality of forgings meets the requirements of forging technical standards and meets the requirements of design, processing and use

the improvement of total factor productivity of forging will play a greater role. The inspection of part quality includes the inspection of appearance quality and internal quality. Appearance quality inspection mainly refers to the inspection of geometric dimension, shape, surface condition and other items of forgings; The inspection of internal quality mainly refers to the inspection of chemical composition, macro structure, microstructure and mechanical properties of forgings

specifically, the appearance quality inspection of forgings is to check whether the shape and geometric dimensions of forgings comply with the provisions of the drawing, whether there are defects on the surface of forgings, what kind of defects they are, and what their morphological characteristics are. The inspection content of surface state is generally to check whether there are surface cracks, folds, wrinkles, pressure pits, orange peel, blisters, scars, corrosion pits, bumps, foreign objects, underfilling, pits, meat shortages, scratches and other defects on the surface of forgings. The inspection of internal quality is to check the internal quality of the forging itself, which is a quality condition that cannot be found by the appearance quality inspection. It includes not only the inspection of the internal defects of the forging, but also the inspection of the mechanical properties of the forging. For important parts, key parts or large forgings, chemical composition analysis should also be carried out. For internal defects, we will inspect whether the forgings have defects such as internal cracks, shrinkage cavities, porosity, coarse grains, white spots, dendritic crystals, flow lines that do not conform to the shape, flow lines disorder, through flow, coarse-grained rings, oxide films, delamination, overheating, overburning structures, etc. through low magnification inspection, fracture inspection, and high magnification inspection. For mechanical properties, it is mainly to check the tensile strength at room temperature, plasticity, toughness, hardness, fatigue strength, high-temperature instantaneous fracture strength, high-temperature endurance strength, endurance plasticity and high-temperature creep strength

because the stress, importance and working conditions of forgings are different in the process of use, and the materials and metallurgists used are also different. Therefore, forgings are divided into categories in different parts according to the above situation and the requirements of this department. Different departments and different standards classify forgings differently. However, as a whole, the quality inspection of forgings cannot be separated from two types of inspection, namely, the inspection of appearance quality and internal quality. It is only that the categories of forgings are different, and their specific inspection items, inspection quantities and inspection requirements are different. For example, some industrial departments divide structural steel, stainless steel and heat-resistant steel forgings into class IV for inspection, some departments divide aluminum alloy forgings and die forgings into class III for inspection according to their use, and others divide aluminum alloy and copper alloy forgings into class IV for inspection. Table 1 do not plug and unplug all kinds of control boards and plugs with power-1 is the inspection requirements for structural steel, stainless steel and heat-resistant steel forgings classified into class IV, and table 1 is the quality inspection requirements for aluminum alloy forgings and die forgings

except for individual items of individual categories, the quality inspection of forgings has the nature of sampling inspection. If the sampling inspection is qualified, it means that the forgings of the whole acceptance batch meet the requirements. For some types of forgings, non inspection items are specified, which cannot be considered as not being controlled. Instead, corresponding quality assurance measures are taken in production, such as raw material re inspection system, forging setting system, periodic inspection system, process discipline inspection system and reasonable batch, so as to simplify the inspection process and ensure the use requirements on the premise of ensuring the quality of forgings

in a word, the content of forging quality inspection covers a wide range and many items. In practical work, the forging quality inspection should be carried out according to the requirements of the design for products and the items required by technical materials

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