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Hot-rolled seamless steel pipe defect

Size-tolerance

1 uneven wall thickness
Features: steel pipe in the same section of uneven thickness, the big difference between the maximum wall thickness and minimum wall thickness.

2 wall thickness of ultra-poor
Features: pipe wall thickness one-way ultra-poor, ultra-positive deviation is called extra-thick wall thickness; the negative deviation is called ultra-thin wall thickness.

3 outside diameter ultra-poor
Characteristics: excessive pipe diameter, ultra-positive poor who called the large outer, the negative difference is called a small outer diameter.

bending
Features: steel pipe along the length direction is not straight or in the pipe end showing the goose-shaped bend called "goose head bent".

5 length of the ultra-poor
Characteristics: length of steel pipe beyond the requirements of super is poor, said foot in length, ultra-negative difference, short feet.

The outer surface defects

1 outside the fold
Features: steel pipe outer surface showing spiral layered folded.

2 bed separation
Features: stratification and rupture of the steel pipe surface showing spiral or block.

3 outside the scarring
Features: steel pipe outer surface showing the spot scar.

4 Ma Face
Features: steel pipe surface rendering rugged Ma Hang.

5 Green Line
Features: steel pipe outer surface showing symmetric or asymmetric linear rolling marks.

6 hairline
Features: steel pipe external surface of the present continuous or discontinuous hair-like fine lines.

7 net cracks
Features: steel external surface of the ribbon and pitch of scaly crack.

8 bumps
Features: steel pipe outer surface due to collisions irregular scars.

9 straightening concave
Features:spiral steel exterior appear before the concave.

10 crack
Features: steel pipe surface opened the rupture phenomenon, mostly generated in thethin-walled tube.

The inner surface defects

1 within the fold
Features: on the inner surface of the steel pipe rendered straight or spiral, half spiral serrated defects.

2 within the scar
Features: steel pipe inner surface showing the spot scars, generally do not take root easily peeled off.

3 warp
Features: steel pipe inner surface presents the nail-like tilt of the straight line or intermittent skin. Appear in the capillary head, and easy to peel off.

4 within the straight
Features: in the steel tube surface has a certain width and depth of linear scratch.

5 within the edge
Features: in the steel tube surface has a certain width and depth, linear raised.

6 pull-concave
Features: steel pipe inner surface showing a regular or irregular pits and outer surface without damage.

speedfit 2012-6-14 17:09:14 回复该留言
Galvanized steel pipe is generally connected by threads on either end of a length of pipe. A small amount of adhesive is typically placed on the threads before screwing them together, in order to reinforce the connection.

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