The existence of defects in titanium forgings may affect the processing quality or processing 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. 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, according to the nature of the defect and the degree of impact on the use, it can take remedial measures for the titanium forgings made to meet the technical standards or requirements of use.
Therefore, in a certain 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 the requirements of design, processing 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 dimensions, shape, surface condition and other items of titanium forgings; the internal quality inspection mainly refers to the inspection of the chemical composition, macrostructure, microstructure and mechanical properties of titanium forgings.
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 is defective, what is the nature of the defect, and what are 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 peels, 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 be analyzed for chemical composition. 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 at normal temperature, plasticity, toughness, hardness, fatigue strength, high-temperature instantaneous fracture strength, high-temperature endurance strength, endurance plasticity and high-temperature creep strength.
After the titanium forgings are made into parts, their stress, importance and working conditions are different during use, and their materials and metallurgical processes are also different. Therefore, titanium forgings are divided into different parts according to the above conditions and in accordance with the requirements of this department. The classification of titanium forgings is different in different categories, different departments, and different standards. But no matter what, the overall quality 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.