The difference between the blast and sand blasting

The difference between the blast and sand blasting
Blasting is the use of high-speed rotation of the impeller to small steel balls or small iron shot throwing out high speed impact surface of parts, so it can remove the oxide layer on the surface of the parts. Pills for steel or iron, at the same time high speed impact parts surface, cause the deformation of lattice distortion on the surface of the parts, the surface hardness is higher, is a kind of parts to clean the surface of the method, blasting are commonly used to clean on the surface of the casting or to strengthen the part surface.
The general rules of blasting is used to shape, such as several thrown together around the head, high efficiency and low pollution. Shipbuilding, shot blasting, sand blasting is widely used. But being shot or sand, were used in the form of compressed air. Of course not shot blasting is to use high-speed rotating impeller. In repair, shipbuilding industry, in general, the shot (steel shot) muti-purpose in steel plate pretreatment (cleaning before coating); Sandblasting (repair, shipbuilding industry with ore) multi-purpose in forming of ship or segmented, is used to get rid of the old paint and rust on sheet metal, coating again. In repair, shipbuilding, shot blasting, sand blasting, the main effect is to increase steel plate coating paint adhesion.
Actually casting parts cleaning not just using the blasting, for large general first roller deoxidization and is put castings riser after resection of the drum roll, by parts collide with each other within the cylinder, the sand on the surface of the most clear first and then to blasting or peening. Blasting balls size is 1.5 mm.
Research shows that in terms of damage, and metal materials surface tensile stress is easier than compressive stress, when the surface is compressive stress, the fatigue life of material is greatly increased, therefore, for shaft parts easy to fatigue fracture, such as usually adopts shot peening forming surface compressive stress, increase product life, in addition, the metal is sensitive to tensile metal materials, this is the tensile strength of the material is more than the low compression strength of the reasons, this also is metal material tensile strength (yield, tensile) is commonly used in the cause of the said material performance.
Our daily car plate in the face of shot peening is used to strengthen, can significantly improve the fatigue strength of materials.
Sandblast for complex shape, easy to use manual derusting, efficiency is not high, the environment is bad, uneven derusting. General sandblasting machine has a variety of specifications of the sand blasting gun, as long as not particularly small cabinet, can put the gun in a clean. Pressure vessel products - head adopts the sandblasting method to remove oxide skin on the surface of the workpiece, quartz sand diameter from 1.5 mm to 1.5 mm.
There is a kind of processing which used water as the carrier, drive the emery to machining a part, is a kind of sandblasting.
Blasting with sand blast to the workpiece have cleared decontamination, with the purpose to prepare for the next sequence, namely to ensure the roughness requirements of next working procedure, also some consistency, in order to surface peening has reinforcement to the workpiece, sandblasting is not obvious. Generally shot peening for small steel ball, gush arenaceous quartz sand. In accordance with the requirements of different mesh.
Precision casting almost use sand blasting, shot blasting every day .