Inquiries : 309 - 2018/8/13 10:24:10
Stainless steel seamless pipe is a long strip of steel with hollow section and no joints around it.
First, the thicker the wall thickness of this product, the more economical and practical it is, and the thinner the wall thickness, the higher the processing cost will be; Secondly, the process of the product determines its limited performance, generally seamless steel pipe accuracy is low: uneven wall thickness, low brightness inside the tube exterior, high scale cost, and the interior surface also has black spots, not easy to remove; Third, its detection and plastic must be off-line processing. Therefore, it embodies its superiority in high pressure, high strength and mechanical structure materials.
The rolling method are divided into hot rolling, hot extrusion and cold drawing. According to the microstructure of stainless steel, semi-ferrite semi-martensite stainless steel pipe, austenitic ferrite iron stainless steel tube and so on.
4 stainless steel pipe specification and appearance quality
A, according to GB14975-94 "stainless steel seamless pipe" regulation, the steel tube usually length (not fixed) hot rolled steel tube 1.5m 10m, hot extruded steel pipe equal to and more than 1m. The wall thickness of cold-drawn steel tube (0.5~1.0mm) is 1.07m, and that of 1.0mm is 1.5m.
B, 45 kinds of diameter 54~480mm and 36 kinds of wall thickness 4.5~45mm of hot-rolled (hot-extruded) steel pipe. There are 65 kinds of diameter 6~200mm and 39 kinds of wall thickness 0.5~21mm of cold-drawn (rolled) steel pipe.
C. There shall be no cracks, folds, cracks, folding, cracks, laminated layers and scarring defects on the inner and outer surfaces of the steel tube. These defects shall be completely removed (except for pipes for mechanical processing), and the wall thickness and outer diameter shall not exceed the negative deviation after removal. Any other minor surface defects not exceeding the allowable negative deviation may not be removed.
D. the depth of the straight is allowed. Hot rolled and hot extruded steel tubes, 5 with diameter less than or equal to 140mm, with maximum depth not greater than 0.5 mm; cold drawn (rolled) steel tubes not greater than 4 parts of nominal wall thickness, maximum depth not greater than 0.3mm.
E, steel pipe ends should be cut into right angles, and remove burrs.