Comprehensive quality of steel grit

　　Steel grit is the most commonly used metal abrasive in shot blasting machines. It is widely used in mechanical processing, anti-corrosion treatment and other fields. So what are the testing standards for steel grit?

　　1. If the steel grit is too soft, it will slow down the cleaning speed and reduce work efficiency. During sandblasting strengthening, steel sand that is too soft cannot produce suitable residual stress, and the force of low-hardness sand cannot be compensated by increasing the impact time. If the hardness is too high, it will produce an unsatisfactory surface morphology, increase the probability of sand breakage, cause excessive consumption, cause greater wear and tear on the equipment, and increase equipment maintenance costs. Therefore, appropriate hardness is also critical.

　　2. The carbon content should be moderate. Silicon and manganese can improve the strength and hardness of steel grit, so it should be as high as possible. Sulfur and phosphorus are harmful elements that can easily make steel grit brittle and lead to premature rupture, so they should be as low as possible.

　　3. The microstructure of steel grit can resist deformation and reduce energy loss and increase fatigue life when acting on the working surface. Tempered martensite is more fatigue-resistant. In addition, brittle carbides need to be reduced in the microstructure, otherwise it will cause premature rupture of steel grit and increase consumption.

　　4. Fatigue life is the ability of steel grit to resist breakage when it acts on the working surface. Abrasives with longer fatigue life will become economical abrasives if they can convert appropriate energy into cleaning.

　　5. Due to the production process used, steel grit will always have certain physical defects. Corresponding processes must be controlled during production to reduce the proportion of defective particles.