How does the forging factory ensure the quality of the forgings?

The inspection of forgings has the nature of random inspection. If the sample is qualified, it means that the entire accepted forging is qualified. Secondly, different types of forgings have different inspection items.

How to ensure the quality of forgings, so that sampling is representative?ForgingsTechnical standards, production technology and technical management system, there are corresponding measures to cooperate. Different factories are not exactly the same, but roughly as follows.

1. raw material re-inspection system

The technical standard for shaft forgings stipulates that raw materials need to be re-inspected according to the melting furnace number before they can be put into production after passing the standard; raw materials undergo head management and ultrasonic inspection. The so-called head management, refers to the raw steel ingot riser end need to be marked with a special mark. During the re-inspection of materials, samples shall be taken from the riser end for inspection. If the raw material of the riser end is qualified, the quality of the rest will generally not be a problem.

Ultrasonic inspection refers to the ultrasonic inspection of raw materials one by one to inspect internal metallurgical defects and ensure that the quality of raw materials put into production meets the standards. Exposing metallurgical defects before production is not only economical, but also simpler and more accurate than flaw detection on forgings.

2. forging type and change system

Shaft forgings can only be put into mass production after the process is finalized.ForgingsThe process is the forging process, which refers to the whole process of raw materials from the beginning of the material, through forging, heat treatment, to the cutting and processing of forgings. When shaping, the inspection items of forgings are more than those in the above table, including sampling in different parts and directions and quality items that may be affected by forging process. For important and complex shape forgings, the process can only be finalized after trial processing and product use.

Ensure the stability of the shaping process and shall not be changed at will. After the process is finalized, it must be strictly implemented. If it is to be changed, it must be studied and approved. When the forgings are transferred to the factory or the dominant process is changed, the situation should be distinguished, re-identified and finalized. In order to improve the process, accumulate experience and test the stability of the forging process, the process can be specially tested. Generally, it is carried out once on a regular basis or after each production of a certain number of forgings. There are more test items, sampling positions and quantities for process-specific inspection than those for normal inspection.

Reasonable batch in 3. production

Each batch of shaft forgings for acceptance shall be composed of forgings with the same drawing number, the same smelting furnace number and the same batch number. Forgings supplied in the final heat treated condition shall also consist of forgings from the same heat treatment furnace. Referred to as "three with" and "four". This batch is determined from the factors that affect the quality of forgings.

Therefore, the same drawing number has the same forging process; the same melting furnace number has the same smelting basis and the same sensitivity to the forging process; the same production batch number and the same heat treatment furnace have the same forging and heat treatment conditions. This group batch is reasonable and the most stringent. In actual production, we should start from the stability of material quality and forging quality, forging type and convenient production, etc.ForgingsUnder the premise that the quality and assurance sampling inspection is representative, it is allowed to relax the group batch conditions appropriately.