Details of ASTM A335 P22 seamless steel pipes commonly used in industrial projects

1. The product should comply with TSG D7002 pressure piping component type test rules,
2. Product specifications of ASTM A335 P22 seamless steel pipes: outer diameter 21.3mm~762mm, wall thickness 2.0~140mm.
3. Chemical composition of ASTM A335 P22 seamless steel pipes: carbon: 0.05~0.14, manganese: 0.30~0.60, phosphorus: ≤0.025, sulfur ≤0.025, silicon: ≤0.50, chromium: 1.90~2.60, molybdenum: 0.87~1.13. Nickel: ≤0.50
4. Tensile strength of ASTM A335 P22 seamless steel pipes: ≥415MPa, yield strength: ≥205, elongation: ≥30, hardness: less than or equal to 163HBW
5. ASTM Production methods of A335 P22 seamless steel pipe: cold drawing, hot rolling, hot expansion. Delivery status: heat treatment.

Process quality, surface quality, and appearance of ASTM A335 P22 seamless steel pipe
The steel pipe factory should find a sufficient number of visible surface defects for measurement to ensure that the depth of the defects has been properly evaluated. It is not necessary to find all surface defects for measurement, but it must be guaranteed to be consistent with the requirements. When the penetration depth of the surface defect exceeds 12.5% of the nominal wall thickness or infringes the minimum wall thickness, it should be considered a harmful defect. Steel pipes with such defects should be treated in one of the following ways:

If the remaining wall thickness is still within the specified range, such defects can be ground away with a grinding wheel. Repair according to the welding repair regulations of relevant requirements.

Within the allowable length range, a section of the pipe containing defects in the pipe length can be cut off.

To provide a good surface and meet the conditions of the judgment, the pipe manufacturer should grind and remove the following defects:

Mechanical scratches, scratches, pits, and other defects with a depth greater than light (1.6mm).

Note: Scores and abrasions are defined as wire rope scratches, collisions, rail scratches, mill scratches, steel ball scratches, scars steel die scratches, and similar causes. Visible defects with a depth greater than 5% of the nominal wall thickness when measured according to relevant requirements are commonly used: flaws, scars, wrinkles, scratches, or burrs.

If the surface defects are acceptable according to relevant requirements, but they do not appear in a scattered manner, but exist in a large area and do not meet the requirements of good appearance, then according to the buyer's opinion, the steel pipe should be rejected. The treatment of such steel pipes should be negotiated by the steel pipe manufacturer and the buyer. When grinding away defects or harmful defects with a grinding wheel, a smooth transition surface should be maintained, and the wall thickness at this location should not be reduced to less than the allowable value specified in this standard. The outer diameter of the grinding point can be reduced due to grinding. The wall thickness should be measured by a mechanical caliper or a correctly calibrated non-destructive testing instrument with a certain accuracy. In case of dispute, the measurement from the caliper should prevail.