For steel pipe commonly used in epoxy, ethylene, phenolic, such as anti-corrosion coating construction technology, the general requirements of the surface of the steel tube to achieve near-white (Sa2.5). Practice has proved that the use of this descaling grade can almost eliminate all the oxide skin, rust and other dirt, the depth of the anchor to reach the 40~100μm, fully meet the adhesion requirements of anti-corrosion layer and steel pipe, and shot blasting machine steel sand steel pill rust removal process can be lower operating costs and stable and reliable quality of near-white (Sa2.5) technical conditions.
In order to achieve the ideal derusting effect, according to the hardness of the steel tube surface, the original degree of rust, the required surface roughness, coating type, etc. to select the abrasive, for Single-layer epoxy, two or three-layer polyethylene coating, steel sand and steel balls of the mixed abrasive more easily achieve the ideal derusting effect. The steel pill has the function of strengthening the steel surface, while the steel sand has the function of etching the steel surface. Steel-sand and steel-pill mixed abrasives, usually the hardness of the steel pill is 40~50 HRC, steel sand hardness of 50~60 HRC can be used in a variety of steel surface, even if used in C-Class and D-class rust on the steel surface, rust effect is also very good, reasonable steel shot steel sand mixing can be used for shot blasting machine has a reasonable use.