The existence of defects in titanium forgings may affect the machining quality or machining quality of subsequent processes, and some seriously affect the performance and use of titanium forgings, and even greatly reduce the service life of the manufactured parts and endanger safety. Specifically, the appearance quality inspection of titanium forgings is to check whether the shape and geometric dimensions of titanium forgings conform to the stipulations of the drawings, whether the surface of titanium forgings has defects, what kind of defects, and their morphological characteristics. The inspection content of the surface condition is generally to check whether the surface of the titanium forging has surface cracks, folds, wrinkles, pits, orange peel, blisters, scars, corrosion pits, bruises, foreign objects, underfill, pits, lack of meat, Defects such as scratches.
The internal quality inspection is to check the internal quality of the titanium 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 titanium forgings, but also checking the mechanical properties of the titanium forgings. Or large-scale titanium forgings should also carry out chemical composition analysis. For internal defects, we will use low-power inspection, fracture inspection, and high-power inspection to check whether titanium forgings have internal cracks, shrinkage holes, looseness, coarse grains, white spots, dendrites, and streamlines that do not conform to the shape and streamlines. Disturbance, flow through, coarse crystal ring, oxide film, delamination, overheating, overfire tissue and other defects. The mechanical properties are mainly to check the tensile strength, plasticity, toughness, hardness, fatigue strength, high temperature instantaneous fracture strength, high temperature endurance strength, endurance plasticity and high temperature creep strength of normal temperature.
After titanium forgings are made into titanium parts, their stress conditions, importance levels, working conditions are different during use, and their materials and metallurgical processes are also different. Therefore, titanium forgings are used in different parts according to the above conditions and in accordance with the requirements of this department. Divided into categories, different departments, different standards for the classification of titanium forgings are also different. But no matter what, the overall inspection of titanium forgings is inseparable from the two major types of inspections, namely the inspection of appearance quality and internal quality, but the types of titanium forgings are different, their specific inspection items, inspection quantities and inspection requirements It’s different. For example, some industrial departments classify structural steel, stainless steel, and heat-resistant steel titanium forgings into category IV for inspection, some departments divide aluminum alloy titanium forgings and die titanium forgings into category III for inspection according to their use, and some departments will Aluminum alloy and copper alloy titanium forgings are classified into category Ⅳ for inspection.
Therefore, in order to ensure or improve the quality of titanium forgings, in addition to strengthening quality control in the process and taking corresponding measures to prevent the occurrence of defects in titanium forgings, necessary quality inspections should also be carried out to prevent any subsequent processes (such as heat treatment, surface treatment, Cold working) and the use of titanium forgings with defects that have a bad influence on the performance of the subsequent processes. After quality inspection, it is also possible to take remedial measures for the manufactured titanium forgings according to the nature of the defects and the degree of impact on use, so as to make it comply with the technical standards or requirements of use. In a sense, the quality inspection of titanium forgings is on the one hand to check the quality of the titanium forgings made, on the other hand is to point out the direction of improvement for the forging process, so as to ensure that the quality of titanium forgings meet the requirements of titanium forging technical standards, and meet Requirements for design, machining and use. The inspection of the quality of titanium forgings includes the inspection of appearance quality and internal quality. The appearance quality inspection mainly refers to the inspection of the geometric size, shape, surface condition and other items of the titanium forging; the internal quality inspection mainly refers to the inspection of the chemical composition, macrostructure, microstructure and mechanical properties of the titanium forging.