Hot-rolled seamless steel pipe defects

Hot-rolled seamless steel pipe defects
Separated
Located in the vertical distribution of the steel tube surface, a spiral rise, massive metal separation or fracture-like stripping.


Straight in the valve
Located in the steel pipe is vertical distribution of the surface, was symmetrical or single-line, with long fold, there are local.


Irregular holes
Located in the pipe surface was vertically distributed, that is, one or two walls 180 ° outwards thickened, or wall thickness at the wall surface separation and thickening of the mandrel shape, also known as the inner drum assembly. Steel garden hexagonal uneven thickness, also known as hexagonal.


Wall shrinks
The inner surface of the steel pipe is located in the depression of the inner surface of the steel pipe with the thinnest cross-section of the steel pipe, the local thinning, the serious shrinkage of the wall thickness, almost tearing.


Scratch
The inner surface of the nail is longitudinally like an indentation of the inner tube surface that is scared, lugged, or lump folded.


Within the fold
Located in the inner surface of the end of the pipe, local or sheet longitudinal spiral or semi-spiral fold irregular distribution.


roll
Located on the longitudinal surface of the pipe wall partially or entirely on the outer surface of the outer corrugated bellows open long symmetrical through the longitudinal grooves, the general straight, slanted individuals.


Tearing
In the longitudinal direction of the steel, the steel surface presents different degrees of transverse rupture, diamond-shaped, oval, through the tubular body.


Double folding
Located in the longitudinal wall surface of the longitudinal extension of a pair of longitudinal cracks, and sometimes scattered in the pipe circumference scattered cracks sometimes appear symmetrical.


Double insert
Located in the longitudinal wall surface of the longitudinal extension of a pair of longitudinal cracks, and sometimes scattered in the pipe circumference scattered cracks sometimes appear symmetrical.


Out of the fold
1. The outer tube is a regular folding triangle, double-stitched straight seam or irregular fold sheet. ② presents a general continuous or intermittent sewing machine or staggered 60 °°, 120,180 ° slit longitudinally folded tube. ③ longitudinally outside the spiral pipe. ④ Longitudinal pipe surface after a long or short slash point fold serious staggered two or three 120 °.