L roundness: circular cross section of the rolled products, such as round steel and round steel pipe cross section, the diameter of the all directions...
L roundness: circular cross section of the rolled products, such as round steel and round steel pipe cross section, the diameter of the all directions
2 shape is not correct: rolling cross-section geometry skew, uneven. Six Angle steel, such as six edge range, large Angle steel apex Angle and steel twist, etc
3 thickness: the thickness of the steel plate (or strip) each place is different, some among both thick and thin, some thin and middle thick of edge, also some poor end in excess of the prescribed
4 bending: rolled piece in length or width is not straight, the curve shape
5 rocker: the length of the steel plate (or strip) direction in the horizontal plane bending to one side
6: curvature of ladle steel plate (or strip) in length and width direction at the same time in the rugged wave phenomenon, making it a "PiaoXing" or "boat"
7 reverse: strip rolled piece along the longitudinal axis twisted into a spiral
8 party, to take off the moment: square, rectangular section material range of edge or diagonal section
9 marks (row) : straight groove shape, visible to the naked eye to groove steel distribution of partial or full length
10 crack: generally in a straight line, sometimes in Y, much the same as that of drawing, but there are other directions, general openings for the acute Angle
Ll double skin (scar) : the surface of the tongue shaped or scales cock chips: one kind is connected with steel frame, and reduced the surface is not easy to fall off; The other is a did not link with steel frame, but the adhesion to the surface is easy to fall off
12 fold: steel partial overlap, there is a clear fold lines
13 rust: surface generated by the rust, its color from apricot yellow to dark red, derusting, after serious corrosion pitting
14 hair tattoos: surface grain is very shallow depth, the width of the tiny hair fine lines and extension of tiny WenLv generally along the rolling direction
15 layers: steel cross section on local clear separation of metal structure, serious when others were divided into 2 ~ 3 layers, there are visible to the naked eye between layer and layer of inclusions
Bubble: the distribution of irregular surface is round, big and small convex hull, its outer edge is smooth. Most is the bulgy, some not pluck up and shine after pickling flat surface, the layered shear section
17 pitting (pits) : surface rendering local or continuous piece of rough surface, the distribution of different shapes, sizes, different pits, serious from time to tome like orange peel shape, than the hemp spot pitting large and deep
18 oxidation color: steel plate (or strip) on the surface of annealed present a light yellow, dark brown, shallow blue, dark blue or light gray, etc
: 19 roller surface of strip or flake of periodic roll printing, its stamping parts is bright, with no obvious protruding sunken feeling
No density of osteoporosis: 20 steel performance. Slice after acid erosion, expanded into many caves, according to its distribution can be divided into: general loose loose, center
2 l segregation: each part of the chemical composition and non-metallic inclusions in steel is not evenly distributed. According to its form of expression can be divided into: dendritic, square shape, punctate segregation and inverse segregation, etc
Residual: 22 shrinkage cavity in the center of the transverse specimens acid leaching, irregular holes or cracks. Holes or cracks tend to remain in the foreign material
Non-metallic inclusions: 23 on the transverse specimens acid see some metallic luster, ashen white, beige and dark gray color, is in steel residual oxide, sulfide, silicate, etc
24: metal inclusions on the transverse specimens at low see some metallic luster and the base metal is obviously different metal salts
25 burnt: to observe the microstructure after erosion, often around the reticular oxide matrix metal can be seen on decarburization, other metals such as copper and its alloy are copper oxide along the grain boundary in network shape or point extends to the inside the sample
26 points: it is one of the steel internal fracture. On the longitudinal fracture of steel assumes the circular or oval silvery white spots, after polishing and acid etching on the transverse section of the performance for the long thin flakes, sometimes radiating distribution, sometimes it is parallel to the direction of deformation or distribution without rules
27 coarse grains: acid leaching test clips on the mouth has a strong metallic luster
28 decarburization: the surface of carbon steel is the inner carbon points to reduce the phenomenon known as decarburization. The decarburization layer refers to the surface of the steel because of decarburization and show all organizations for ferrite part; Part decarburization refers to after the decarburization layer to the carbon content of steel is not reduce)
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Difference of PSL1 and PSL2(API 5L)
The API 5L has two standards, PSL1 and PSL2, which are very different from each other. I'll talk more about the differences between PSL1 and PSL2.
Production Process of Pipe Fitting
There are many kinds of processing methods for pipe fittings.
The Future of Steel Pipe Development
The future of steel pipe development is looking promising, according to expert analysis and data. The price of carbon steel pipe is predicted to bounce back this year, with China leading the way in increasing steel consumption demands. This is due to a series of government initiatives aimed at stimulating domestic demand, including the construction of affordable housing and infrastructure projects. The demand for structural steel pipe is also on the rise, thanks to state investment in housing and engineering projects. With private investment projects also gaining popularity, the steel pipe market is set to thrive in 2017.
