How To Check The Quality Of Steel Shot And Sand?

Steel shot is one of the commonly used abrasives, which is made of selected raw material scrap steel. Steel shot is often used for the treatment of metal surface. The products treated with steel sand can meet the national standards.
High quality steel sand products have moderate hardness, strong toughness, impact resistance, can be used repeatedly for several times in succession, and also have many characteristics such as long service life, good resilience, strong adhesion, fast cleaning speed, low sand consumption, no breakage, large brightness of cleaning workpiece, and good technical effect.
Of course, this is the advantage of high-quality steel sand. The treatment effect of inferior steel sand is greatly discounted. How to test the quality of steel sand?
1、 Hardness. If the steel sand is too soft, it will slow down the cleaning speed and reduce the work efficiency. During sand blasting, too soft steel sand cannot produce suitable residual stress, and the force of low hardness sand cannot be compensated by increasing impact time. If the hardness is too high, it will produce undesirable surface morphology, increase the probability of sand breaking, make the consumption too high, and wear the equipment greatly, increase the equipment maintenance cost, so the appropriate hardness is also very important.
2、 Microstructure. The microstructure of steel sand must be able to resist deformation and reduce energy loss and fatigue life when acting on the working face. Tempered martensite is fatigue-resistant. In addition, brittle carbides must be reduced in the microstructure and microstructure, otherwise it will cause premature fracture of steel sand and increase the usage.
3、 Chemical composition. It determines the microstructure of steel sand and the effect of subsequent heat treatment. The carbon content should be moderate. Silicon and manganese can improve the strength and hardness of steel sand, so it should be as high as possible. Sulfur and phosphorus are harmful elements, which are easy to make steel sand brittle and lead to premature fracture, and should be as low as possible.
4、 Fatigue life. Fatigue life is the ability of steel shot sand to resist crushing when it acts on the working surface. Abrasives with longer fatigue life will become economic abrasives if it can convert appropriate energy into cleaning.
5、 Physical defects. The steel sand must contain as few physical defects as possible that may cause abrasive fracture. Due to the production process used, steel sand will always have such physical defects. During production, there must be corresponding procedures to control and reduce the proportion of defective particles.