The existence of defects in titanium forgings can affect the quality of subsequent processing or processing, while others seriously affect the performance and use of titanium forgings, and even greatly reduce the service life of the finished parts, endangering 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 titanium forgings with defects that have adverse effects on subsequent processes (such as heat treatment, surface treatment, cold processing) and performance from flowing into subsequent processes. After quality inspection, remedial measures can also be taken for the made titanium forgings based on the nature of the defects and the degree of impact on their use, so that they meet technical standards or usage requirements.
Therefore, in a sense, the quality inspection of titanium forgings is to control the quality of the already made titanium forgings, and to point out improvement directions for the forging process, in order to ensure that the quality of titanium forgings meets the requirements of titanium forging technical standards and meets the requirements of design, processing, and use. The quality inspection of titanium forgings includes the inspection of appearance quality and internal quality. 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 various items such as the chemical composition, macroscopic structure, microstructure, and mechanical properties of titanium forgings.
Specifically, the appearance quality inspection of titanium forgings refers to checking whether the shape and geometric dimensions of titanium forgings comply with the specifications of the drawings, whether there are defects on the surface of titanium forgings, what kind of defects they are, and what their morphological characteristics are. The inspection content of surface condition is generally to check whether there are surface cracks, folds, wrinkles, pits, peeling, blistering, scars, corrosion pits, bumps, foreign objects, underfilled, dents, missing flesh, scratches and other defects on the surface of titanium forgings. The inspection of internal quality is to check the internal quality of titanium forgings themselves, which is a quality condition that cannot be detected by appearance quality inspection. It includes both checking the internal defects of titanium forgings and checking the mechanical properties of titanium forgings. Chemical composition analysis should also be performed on important, critical, or large titanium forgings. For internal defects, we will use methods such as low magnification inspection, fracture inspection, and high magnification inspection to inspect titanium forgings for defects such as internal cracks, shrinkage, porosity, coarse grains, white spots, dendritic crystals, flow lines that do not conform to the shape, flow lines that are disordered, flow through, coarse grain rings, oxide films, delamination, overheating, and burnt structures. For mechanical properties, it mainly involves checking room temperature tensile strength, plasticity, toughness, hardness, fatigue strength, high-temperature instantaneous fracture strength, high-temperature endurance strength, endurance plasticity, and high-temperature creep strength.
Due to the different stress conditions, importance, and working conditions during the use of titanium forgings made into parts, as well as the different materials and metallurgical processes used, titanium forgings are classified according to the above conditions and requirements in different parts. Different standards also classify titanium forgings differently. However, for the overall quality inspection of titanium forgings, there are two main types of inspections, namely appearance quality and internal quality inspection. However, the categories of titanium forgings are different, and their specific inspection items, inspection quantities, and inspection requirements are different.