Method for quality inspection of forgings

The existence of forging defects, some will affect the quality of subsequent processing or processing, and some will seriously affect the performance and use of forgings, and even greatly reduce the service life of the finished product, endangering safety. Therefore, in order to ensure or improve the quality of forgings, in addition to strengthening quality control in the process and taking corresponding measures to eliminate the occurrence of forging defects, necessary quality inspections should also be carried out to prevent subsequent processes (such as heat treatment, surface treatment, cold processing) And forgings with defects that have adverse effects on performance will flow into subsequent processes. After the quality inspection, remedial measures can also be taken for the manufactured forgings according to the nature of the defects and the degree to which they affect the use, so as to make them meet the technical standards or use requirements.

Therefore, in a sense, the quality inspection of forgings, on the one hand, is to check the quality of forgings that have been made, and on the other hand, it is to point out the direction of improvement for the forging process, 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 requirements.

The quality inspection of forgings includes the inspection of appearance quality and internal quality. Appearance quality inspection mainly refers to the inspection of the geometric size, shape, surface condition and other items of the forging; the internal quality inspection mainly refers to the inspection of the chemical composition, macroscopic structure, microstructure and mechanical properties of the forging.

Jiahangero said that specifically speaking, the appearance quality inspection of forgings is to check whether the shape and geometric dimensions of the forgings meet the requirements of the drawings, whether there are defects on the surface of the forgings, what kind of defects are, and what are their morphological characteristics. The inspection content of the surface state is generally to check whether there are surface cracks, folds, wrinkles, pressure pits, orange peel, blisters, scars, corrosion pits, bruises, foreign objects, underfilling, pits, lack of meat, scratches on the surface of forgings. defects such as scratches.

The internal quality inspection 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 checking the internal defects of the forging, but also checking 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 use low-magnification inspection, fracture inspection, and high-magnification inspection to check whether there are internal cracks, shrinkage cavities, looseness, coarse grains, white spots, dendrites, streamlines that do not conform to the shape, and streamline disorder. , flow through, coarse crystal ring, oxide film, delamination, overheating, overheating and other defects. As for the 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 durable strength, durable plasticity and high temperature creep strength, etc.

Since the forgings are made into parts, their stress, importance, and working conditions are different during use, and the materials and metallurgical processes used are also different. Therefore, different parts are divided into categories according to the above conditions and in accordance with the requirements of this department. , Different departments and different standards classify forgings differently. But in any case, the overall quality inspection of forgings is inseparable from two types of inspections, that is, the inspection of appearance quality and internal quality, but the types of forgings are different, and the specific inspection items, inspection quantities and inspection requirements are different.