Forging cleaning is divided into raw material (blank) cleaning, intermediate piece cleaning and forging cleaning. The purpose of cleaning is to improve the surface quality of forgings, improve the cutting and processing conditions of forgings, and prevent the continuous expansion of surface defects.
Forging cleaning includes rod (billet) milling, pickling, sand blasting (shot blasting) and shot blasting cleaning; Pickling, sand blasting (shot blasting) and shot blasting cleaning of forged intermediate pieces and forgings. In very few cases, due to the requirements of environmental protection, the use of pickling is greatly limited. The ferrous metal forging pickling is only used for phosphating and saponification treatment of some cold forging blanks.
In actual forging production, most forgings and forgings are cleaned by sand blasting (ball blasting) and shot blasting. However, how to select cleaning equipment, how to use the working speed of cleaning equipment, and how to select steel grit and steel ball are often ignored by forging enterprises. Many enterprises basically use the standard speed promoted by equipment manufacturers and the materials and dimensions of steel sand and steel balls. There is no substantial experimental (or experimental) research, and there is a great misunderstanding about sand blasting (ball blasting) and shot blasting cleaning. Either the cleaning effect is not good, or the cost is not appropriate, resulting in a certain waste of forging enterprises. In particular, some enterprises did not consider the systematic study of forging cleaning and carefully designed it, which has become an important disadvantage of some forging enterprises.
The development of less oxidation free forging is the eternal direction of forging, but at the current stage of development, we can not completely give up the sand blasting (ball) and ball cleaning process. In the case of using sand blasting (ball) and ball cleaning processes, it is hoped that enterprises can improve the sand blasting (ball) and ball cleaning processes according to the following practices.
Fully understand the characteristics of the purchased equipment (if not purchased, carefully select the working speed (speed, sand blasting or shot blasting speed), processing capacity and applicable cleaning material type of the processing equipment according to the following discussion.
According to the forging materials and the shape (complexity) of the cleaned parts, repeated tests are carried out to determine the cleaning technical parameters. It mainly includes loading capacity, various speed values, sand (ball) material and diameter (or weight), part shape (weight) and material.
For the quality, effect and efficiency of cleaning, every enterprise must carry out experimental (or experimental) research, statistically classify forgings according to experimental (or experimental) data, determine cleaning parameters, and formulate a reasonable cleaning process. Forgings shall not be cleaned at will, and cleaning is also one of the important forging production processes.