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Terms of Steel Defect
Date:2015-11-21      View(s):2413      Tag:carbon steel pipe manufacturer, erw steel pipe manufacturer, seamless steel pipe manufacturer

Roundness: mainly for the circular cross-section rolled products, such as the cross section round and round steel pipe, unequal diameters in all directions. 
Incorrect shapes: skew and uneven geometry of rolled cross-sectional. Such as the unequal-leg  six-sided steel, large apex angle steel and section steel torsion. 
Uneven thickness: steel (or strip) is not the same as the thickness of the various parts, some thick on both sides and thin in the middle, and some thick in the middle and thin at the edges, and some head and tail difference exceeds requirements. 
Bending: rolling is not straight in length or width direction, showing curved. 
Camber: steel plate (or steel) bent to one side in the longitudinal direction in the horizontal plane. 
Scoop curvature: steel (or steel) undulating wave phenomenon occurs simultaneously in length and width directions, making it a "scoop-shaped" or "boat." 
Reverse: strip rolled into a spiral twist along the longitudinal axis. 
Off square, off rectangle: unequal opposite sides and cross-sectional diagonal line of square, rectangular section material.
Scored (drawing stamp): shown linear gully, can be seen in the partial or full-length of the steel. 
Cracks: general shown as linear shape, and sometimes Y-shaped, more consistent with the pulling direction, but there are other directions, the general opening as an acute angle. 
Scarring: the surface is shown as curled tongue or scale piece of sheet: one is linked with the body of steel, and pressed to the surface and not easy to fall off; another is not linked with the body of steel, but stick close to the surface and is easy to fall off. 
Folding: steel surface partially overlapping, with a clear fold lines. 
Rust: rust formed on the surface, its color ranging from yellow to dark red, after the process of rust removal, there are serious corrosion pitting. 
Hairline: the surface hairline is with shallow depth, small width, and tiny hair-like fine lines, generally extending along the rolling direction of the pattern and forming tiny thread. 
Layering: a steel cross-section with a clear partial separation of the metal structure, is even divided into 2 to 3 layers, have visible inclusions between the layers. 
Bubbles: Surface irregularly distributed large and small rounded convex hull, with relatively smooth outer edge. Most is plumped up, some do not muster and the surface shiny and smooth after pickling. 
Pittings: surface showing partial or continuous pieces rough surface, distributing different shapes, different sizes of the pits, a similar serious orange peel-like, large and deep pitting spots. 
Oxidation Color: steel plate (or steel strip) on the surface after annealing showing pale yellow, dark brown, light blue, dark blue or light gray and so on. 
Roll printing: surface with strip or sheet periodically roll printing, which is lighter in the embossed parts, and there is no obvious bumping. 
Loosening: the performance of no density steel. After the slices through the acid erosion, expanded into many caves which can be divided according to their distribution: general porosity, center porosity. 
Segregation: the uneven distribution of chemical composition and non-metallic inclusions in the steel. According to its manifestations can be divided into: dendritic, box-shaped, point-like segregation and anti-segregation. 

Residual shrinkage: in the center of the acid leaching transverse test pieces, showing irregular voids or cracks. 

 

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