How is the appearance inspection of shaft forgings?

2024-08-14 15:35:19

The quality inspection of shaft forgings is divided into appearance quality inspection and internal quality inspection.

Generally speaking, the inspection of appearance quality is a non-destructive inspection, usually carried out with the naked eye or a low-power magnifying glass, and if necessary, non-destructive testing methods are also used.

The non-destructive testing methods commonly used for quality inspection of shaft forgings include magnetic particle inspection, penetrant inspection, eddy current inspection, ultrasonic inspection, etc.

Magnetic particle inspection method is widely used to inspect surface or near surface defects of ferromagnetic metal or alloy shaft forgings, such as cracks, streaks, white spots, non-metallic inclusions, delamination, folding, carbides or ferrite bands, etc. This method is only applicable to the inspection of ferromagnetic material shaft forgings and is not suitable for shaft forgings made of austenitic steel. The penetration inspection method can not only inspect magnetic material shaft forgings, but also detect surface defects such as cracks, looseness, folding, etc. of non ferromagnetic material shaft forgings. It is generally only used to inspect surface defects of non ferromagnetic material shaft forgings and cannot detect defects hidden below the surface.

Eddy current testing is used to inspect defects on or near the surface of conductive materials.

Ultrasonic inspection method is used to inspect internal defects of shaft forgings, such as shrinkage cavity, white spot, central crack, slag inclusion, etc. Although this method is convenient, fast and economical, it is difficult to accurately determine the nature of defects.

With the development of non-destructive testing technology, new non-destructive testing methods such as acoustic vibration method, acoustic emission method, laser holography method, CT method, etc. have emerged. The emergence and application of these new methods in the inspection of shaft forgings will greatly improve the level of quality inspection of shaft forgings.

Of course, in practical work, the selection of testing methods and the use of testing methods should be based on the category of shaft forgings and the specified testing items. When selecting test methods and test means, both progressiveness and practicality and economy should be taken into consideration. progressiveness cannot be simply pursued. If you can solve problems with one means, you should not use two or more. The selection of test means should accurately determine the nature of defects and accurately find out the cause of defects as the starting point. Sometimes if the test means are selected too advanced, it will lead to unnecessary consequences and unnecessary losses.