How Do I Perform Quality Inspection On Large Forgings?

The vast majority of large forgings are key parts of machinery and equipment, the quality requirements are particularly strict, and because of the size and size of large, multi-use ingots directly forged, the production process is complex, affecting the quality of forgings a variety of factors and difficult to control, so easy to produce defects and waste, resulting in major economic losses. The contents of the general large forging quality inspection are as follows:

Inspection of forging quality includes inspection of appearance quality and internal quality. The appearance quality inspection mainly refers to the inspection of the geometry, shape and surface condition of the forging, while the internal quality inspection mainly refers to the inspection of the chemical composition, macro-organization, micro-organization and hydraulic performance of the forging.

Specifically, the appearance quality inspection of forgings is to check whether the shape of forgings, geometry conforms to the requirements of the pattern, whether the surface of forgings is defective, what is the nature of defects, what are their morphological characteristics. The inspection content of the surface state is generally to check the surface cracks, folding, folding, creases, pressure pits, orange peels, foaming, scarring, corrosion pits, bruises, foreign objects, not full, pits, lack of meat, scratches and other defects. The internal quality inspection is to check the intrinsic quality of the forging itself, is the appearance quality inspection can not find the quality condition, it includes both the inspection of the internal defects of the forging, but also the inspection of the forging’s hydraulic performance, and important parts, key pieces or large forgings should also be chemical composition analysis.

For internal defects through low-fold inspection, break-checking, high-times inspection methods to verify whether forgings such as internal cracking, shrink holes, loose, coarse crystal, white dot, branch-like crystallization, flow line does not conform to the shape, flow disorder, flow, flow, coarse ring, oxidation film, layering, overheating, over-burning tissue and other defects. For mechanical properties, it is mainly to check the strength, plasticity, toughness, hardness, fatigue strength, high temperature instantaneous fracture strength, high temperature persistence strength, long-lasting plasticity and high temperature creep strength.

Because forgings are made into parts, in the process of use, their force conditions, importance, working conditions are different, the materials used and metallurgical processes are also different, so different parts according to the above-mentioned situation and in accordance with the requirements of the department will be forgings into categories, different departments, different standards of forging classification is also different. However, in any case, for the forging quality inspection as a whole is inseparable from the two categories of inspection, namely, appearance quality and internal quality inspection, but the forging categories are different, its specific inspection items, inspection quantity and inspection requirements are different. For example, some industrial sectors will be structural steel, stainless steel, heat-resistant steel forgings into IV. class inspection, some departments will be aluminum alloy forgings and die forgings according to their use into CLASS III.