Common inspection methods for forged titanium alloy parts:
Titanium alloy products are of good quality. It is very important to inspect the materials before processing. The conventional inspections are as follows:
Chemical composition inspection is generally based on the ingot number of the material for sampling and analysis, rather than separate inspection. Except for important or suspicious forgings, samples shall be taken from the materials for testing, chemical analysis or spectroscopy.
Mechanical property inspection: it must be ensured that the same batch is the same heat number and the same heat treatment process. The inspection mainly includes:
1. Tensile test: determine the strength limit, yield limit, elongation, reduction of area, etc. under unidirectional static tension.
2. Impact test: it is used to test the toughness of materials. Impact test is generally required for parts that are subjected to impact load and vibration load during operation, or work at high temperature and high speed, such as turbine disk, turbine blade, etc.
3. Hardness test: it is a commonly used method in production to judge the mechanical properties of materials. The purpose of hardness test is to ensure normal cutting performance during material processing, judge the decarburization of material surface and understand the uneven degree of internal structure of material. Hardness test is generally carried out after material heat treatment, which can be Brinell hardness or Rockwell hardness.
4. Other tests: for some important or large die forgings or materials working under special conditions, fatigue resistance, bending, torsion, high temperature creep and endurance strength tests shall also be carried out as required.
Visual appearance inspection: This is a common method for inspection between processes. Visually observe whether the material surface has defects such as folding, crack, crush, scar, surface overburning, etc. Deep hidden defects on the material surface are often observed after heat treatment and cleaning.
Dimensional measurement and inspection: including: length, width, height, shape and position tolerance, displacement, etc. Measuring tools include caliper, caliper, micrometer, ring gauge, plug gauge, sample plate, special fixture, etc. inspection instruments that can also be controlled and analyzed by computer, or optical comparator and optical projector can be used for relevant dimensional inspection.
Microscopic examination. That is, under the microscope, observe the metallographic structure of the material, whether there are micro defects, segregation and inclusions, and grade the grain size and non-metallic inclusions.