The existence of defects in TC4 titanium forgings will […]
The existence of defects in TC4 titanium forgings will affect the processing quality or processing quality of subsequent processes, and some will seriously affect the performance and use of titanium forgings and titanium alloy forgings, and even greatly reduce the service life of the finished products 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 adopting corresponding measures to prevent the occurrence of defects in titanium forgings, necessary quality inspections should also be carried out to prevent subsequent processes (such as heat treatment, surface treatment, Titanium forgings with defects that have adverse effects on cold working) and service performance flow into the subsequent process. After the quality inspection, remedial measures can be taken for the manufactured titanium forgings according to the nature of the defect and the degree of influence on the use, so that it meets the technical standards or requirements for use.
Therefore, the quality inspection of titanium forgings in a sense, on the one hand, is to check the quality of the manufactured titanium forgings, on the other hand, it is to point out the improvement direction for the forging process, so as to ensure that the quality of the titanium forgings meets the requirements of the technical standards for titanium forgings. And meet the requirements of design, processing and use. The quality inspection 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 forgings; the internal quality inspection mainly refers to the inspection of the chemical composition, macrostructure, microstructure and mechanical properties of the titanium forgings.
Specifically, the appearance quality inspection of titanium forgings is to check whether the shape and geometric dimensions of the titanium forgings meet the requirements of the drawings, whether the surface of the titanium forgings are defective, what are the defects, and what are their morphological characteristics. The inspection content of the surface condition is generally to check whether the surface of the titanium forgings has surface cracks, folds, wrinkles, pits, orange peel, blisters, scars, corrosion pits, bruises, foreign objects, underfilling, pits, lack of meat, Defects such as scratches. The internal quality inspection is to check the internal quality of the titanium forging itself. It is a quality condition that cannot be found by the appearance quality inspection. It includes the inspection of the internal defects of the titanium forgings and the inspection of the mechanical properties of the titanium forgings. For important and key parts Or large titanium forgings should also be subjected to chemical composition analysis. For internal defects, we will inspect the titanium forgings through low-power inspection, fracture inspection, and high-power inspection to check whether there are internal cracks, shrinkage holes, porosity, coarse crystals, white spots, dendritic crystals, and streamlines that do not conform to the shape and streamlines. Defects such as turbulence, flow through, coarse crystal ring, oxide film, delamination, overheating, and overburning organization. For the mechanical properties, it is mainly to check the normal temperature tensile strength, plasticity, toughness, hardness, fatigue strength, high temperature instantaneous rupture 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 the materials and metallurgical processes used are also different. Therefore, different parts of the titanium forgings are divided according to the above conditions and the requirements of this department. According to different categories, different departments and different standards have different classifications of titanium forgings. But no matter what, the overall quality inspection of titanium forgings cannot be separated from two major types of inspections, namely, the inspection of appearance quality and internal quality, but the types of titanium forgings are different, and the 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, and some departments classify aluminum alloy titanium forgings and die titanium forgings into category III according to their use conditions, and some Aluminum alloy and copper alloy titanium forgings are classified into Category IV for inspection.