Due to titanium forgings made parts, the stress distribution in the process of using, important degree, working condition is different, its materials and metallurgy process is different, so different parts according to the above situation and according to the requirements of the department will titanium forgings to separate categories, different departments, different standards for the classification of the titanium forgings are also different.But no matter how, for the titanium forging quality inspection of the whole is inseparable from two categories of inspection, namely the inspection of appearance quality and internal quality, but the titanium forging of different categories, the specific inspection items, inspection quantity and inspection requirements are different.For example, some industry officials structural steel, stainless steel, heat-resistant steel titanium forging into Ⅳ test in the class, some department will titanium titanium alloy forging and die forging according to its usage into Ⅲ test in the class, and the department of titanium aluminium alloy, copper alloy forgings can be divided into Ⅳ test class.
Specifically speaking, the appearance quality inspection of titanium forgings is to check whether the shape and geometric size of the titanium forgings conform to the requirements of the drawings, whether there are defects on the surface of titanium forgings, what are the defects and what are their morphological characteristics.The inspection of the surface state is generally to check whether there are surface cracks, folds, wrinkles, craters, orange peel, bubbles, spots, corrosion pits, bruises, foreign objects, unfilled, pits, lack of flesh, scratches and other defects on the surface of titanium forging.The inspection of the internal quality is to check the internal quality of the titanium forging itself, which is the quality condition that cannot be found by the inspection of the appearance quality. It not only includes the inspection of the internal defects of the titanium forging, but also includes the inspection of the mechanical properties of the titanium forging.For internal defects, we will use low-power inspection, fracture inspection and high-power inspection to check whether titanium forging has defects such as internal crack, shrinkage cavity, porosity, coarse crystal, white spot, dendritic crystal, streamline disconformity, streamline disorder, penetration, coarse crystal ring, oxide film, stratification, overheating, overheated tissue and so on.For mechanical properties, we mainly check tensile strength, plasticity, toughness, hardness, fatigue strength, instantaneous fracture strength at high temperature, durable strength at high temperature, durable plasticity and creep strength at high temperature.
Some defects of titanium forging will affect the quality of subsequent processing or processing, while others seriously affect the performance and use of titanium forging, and even greatly reduce the service life of the finished products, endangering the safety.So in order to ensure or improve the quality of titanium forgings, in addition to strengthen the quality control in the process, take corresponding measures to put an end to produce titanium forgings defects, should also make the necessary quality inspection, to prevent with the subsequent process (e.g., heat treatment, surface treatment, cold working) and use the defect of bad influences on the performance of titanium forgings to shed the subsequent working procedure.After quality inspection, remedial measures can also be taken according to the nature of the defect and the degree of impact on the use of the titanium forgings, so that they meet the technical standards or use requirements.
Therefore, the quality inspection of titanium forgings, in a sense, on the one hand, is to check the quality of titanium forgings, on the other hand, it is to point out the improvement direction of the forging process, so as to ensure that the quality of titanium forgings conforms to the requirements of the technical standards of titanium forgings, and to meet the requirements of design, processing and use.The inspection of the quality of titanium forgings includes inspection of external quality and internal quality.Appearance quality inspection mainly refers to the inspection of the geometrical size, shape and surface condition of the titanium forging.The inspection of internal quality mainly refers to the inspection of chemical composition, macroscopic structure, microstructure and mechanical properties of titanium forgings.