20# seamless steel
Aug 13, 2018
1.1 the nominal diameter of the steel pipe is 88.9mm, and the nominal wall thickness is 6.45mm.
1.2 the allowable deviation of the outer diameter and wall thickness of the steel pipe should comply with the requirements of Table 1. Allowable deviation of outside diameter and + 0.50mm~0.20mm wall thickness tolerance + 0.97mm~0.77mm.
2 the normal length of the steel pipe is 9400mm~9750mm.
3 shape
3.1 steel pipe bending should not exceed 1.0mm/m.
3.2 the ends of both ends of the steel pipe should be perpendicular to the axis of the steel pipe and the burrs should be removed.
4 the weight of the steel pipe is delivered according to the actual weight, and it can also be delivered according to the theoretical weight. The theoretical weight of the steel pipe is 13.115kg/m per meter.
5. the allowable deviation of the chemical composition of the finished products of the steel pipe should comply with the relevant regulations of GB/T 222.
6. delivery condition of the steel pipe is delivered in hot rolling condition.
7. After proper heat treatment, the mechanical properties of the steel pipe should meet the requirements of N80 grade in API SPEC 5CT.
8. The compact steel pipe should be tested by eddy current flaw detection one by one. The diameter of the artificial defect through-hole of the contrast sample is 2.2 mm (+ 0.01 mm).
As an important part of steel products, steel pipes are divided into two categories: seamless steel pipes (round billets) and welded steel pipes (plates, strips) because of their different manufacturing processes and shapes of tube blanks.
Seamless steel tubes are divided into hot-rolled (extruded) seamless steel tubes and cold-drawn (rolled) seamless steel tubes because of their different manufacturing processes. Cold drawn (rolling) pipes are divided into two types: round pipe and special tube.
