Defects in terms of steel_Steel Pipe knowledge_News

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serial	name,	Description
l	roundness,	circular cross-section of rolled products, such as round and round steel tube cross section of diameter ranging from all directions.
2	shape is not correct	rolled cross-sectional geometry of crooked, uneven. Such as ranging from six angles of the six sides, the angle angle steel to reverse.
3	thickness, uneven	steel plate (or strip) is not the same as the thickness of the various parts, and some on both sides of thick, thin, middle, and some edge thin and intermediate thickness, and some head and tail more than poor requirements.
4	curvature	rolling in the length or width direction is not straight, curved shape.
5	camber	plate (or strip) the length of the direction in the horizontal plane is bent to one side.
6	scoop curvature	steel plate (or strip) in length and width direction at the same time, the ups and downs of wave phenomena, making it a "scoop-shaped" or "boat".
7	reverse	strip rolling along the longitudinal axis of twist into a spiral.
8	, off the side, off the moment	square, rectangular cross-section of materials ranging side or cross section diagonal range.
9	pull marks (The Road)	was the straight line groove-like to the naked eye can see the partial or total length of ditch located in the steel.
10	crack	generally linear shape, and sometimes showed a Y-shaped, with the direction of the pull system, but there are other directions, general openings for an acute angle.
ll	weight, skin (scarring)	surface of the tongue or the tilt of the fish-scale piece of thin slices: one is linked with the steel body, and converted to easy to fall off the surface; another with steel the body is not linked, but adhesion to the surface easy to fall off.
12	The folding	steel surface partial overlap, the folding pattern.
13	The corrosion	surface rust generated by its color from apricot to dark red, rust, severe corrosion pitting.
14	issued the pattern	surface hairline is a very shallow depth, width and tiny hair-like fine lines, and the formation of fine grain thread generally extending along the rolling direction.
15	layered	, steel cross-section on the separation of local metal structure, divided into 2 to 3 layers serious, visible inclusions between the layers.
16	bubbles	surface irregular distribution of the rounded convex hull, large and small, its outer edge is relatively smooth. Most of the muster, and some do not muster the surface of After pickling smooth, shiny, layered cut section.
17	, Ma points (surface Ma)	surface showing partial or continuous into the rough surface, the distribution of different shapes, different sizes of the pits, serious orange peel-like than the pitting large and deep linen spots.
18	oxidation the Color	steel plate (or strip) after annealing on the surface, showing a pale yellow, dark brown, light blue, dark blue or light gray.
19	roll the India	surface of the strip or sheet of periodic roll printing, stamping parts lighter, and there is no obvious punch feeling.
20	loose	steel compact performance. Slice after acid erosion, expanded into many caves, according to the distribution can be divided into: general loose, center porosity.
2l	segregation	The phenomenon of uneven distribution of the various parts of the chemical composition and non-metallic inclusions in steel. According to its manifestations can be divided into: dendritic, box-shaped, point-like segregation and anti-segregation.
22	, shrinkage residual	in the lateral acid leaching the center of the specimen, showing the irregular voids or cracks. Holes or cracks are often remnants of foreign matter.
23	The non-metallic inclusions	in the horizontal acid specimen on to see some non-metallic luster, was gray, beige and dark gray color, residues in the Department of steel oxide, sulfide, silicate salt.
24	The metal inclusions	in the horizontal low specimen see some distinctly different metal salts with a metallic luster and base metal.
25	over the burning	observed microstructure erosion, often in the network-like oxide around the metal matrix can be seen the decarburization organizations, other metals such as copper and its alloys copper oxide along the grain boundary was the network-like or punctate to sample the internal extension.
26	white spots	it is a steel internal rupture. Were round or oval-shaped silver-white spots on the longitudinal fracture of the steel, transverse sections after polishing and etching, slender hair crack, sometimes radiating distribution, and sometimes parallel to the deformation direction or irregular distribution.
27	grain, thick	acid leaching test fragment I have a strong metallic luster.
28	the decarburization	steel, carbon than the inner layer of carbon to reduce the phenomenon known as decarburization. Whole decarburized layer of the steel surface due to the decarbonization and showing all of the ferrite part of the organization; part of the decarburization is to the organization at the carbon content of steel is not reduced after full decarburized layer.