Recommended companies Shandong stainless steel pipe factory share according to the structure of stainless steel pipe classification
(1) High-quality carbon structural steel (GB/T699-1999)
In addition to the carbon (C) element contained in the steel and containing a certain amount of silicon (Si) (generally no more than 0.40%), manganese (Mn) (generally no more than 0.80%, up to 1.20%) alloy elements for deoxidation, Does not contain other alloying elements (except residual elements).
This kind of steel must ensure chemical composition and mechanical properties at the same time. The sulfur (S), phosphorus (P) impurity element content is generally controlled at 0.035% or less. If it is controlled at 0.030% or less, it is called high-quality steel, and its brand name should be added after A", for example, 20A; if P is controlled below 0.025% and S is controlled below 0.020%, it is called premium grade steel, and the grade should be marked with "E" after the grade. Other residual alloys brought into the steel from raw materials The content of elements such as chromium (Cr), nickel (Ni), copper (Cu), etc. is generally controlled at Crl 0.25%, Nil 0.30%, Cul 0.25%. Some grades of manganese (Mn) content reaches 1.40%, Manganese steel.
Such steels rely on adjusting the amount of carbon (C) to improve the mechanical properties of steel. Therefore, depending on the level of carbon content, such steels can be further divided into:
Low-carbon steel - carbon content is generally less than 0.25%, such as 10,20 steel;
Medium carbon steel - carbon content is generally between 0.25 ~ 0.60%, such as 35,45 steel;
High-carbon steel - carbon content is generally greater than 0.60%. This type of steel is generally not used to manufacture steel pipes.
In fact, there is no clear limit to the carbon content between them.
This type of steel has a relatively large output and a wide range of uses. It is usually rolled (forged) into round, square, and flat sections, plates, and seamless steel tubes. It is mainly used for the manufacture of general structures and mechanical structures, components, and structural structures. Pipes for conveying fluids. According to the use requirements, it is sometimes used after heat treatment (normalizing or quenching).
(2) Carbon Structural Steel (GB/700-1999)
This type of steel is generally smelted by a converter or open hearth furnace. Its main raw material is molten iron plus scrap steel. Its sulfur and phosphorus content is higher than that of high-quality carbon structural steel, and its sulfur content is generally 0.05%, and phosphorus is 0.045%. The contents of other alloying elements in the alloy, such as chromium, nickel, and copper, generally do not exceed 0.30%. According to composition and performance requirements, the grades of such steels are Q195, Q215A, B, Q235A, B, C, D, Q255A, B, and Q275. Such as steel grade representation.
Note: "Q" is the Chinese Pinyin capitalized initial of the yielding "Qu", and the subsequent number is the minimum yield point (ss) value of this grade. The following symbol is based on the content of the impurity elements (S, P) of the steel. From high to low and accompanied by changes in carbon and manganese elements, they are divided into A, B, C, and D.
This type of steel has the largest output and is widely used. It is rolled into plates, profiles (round, square, flat, work, groove, angle, etc.) and profiled materials, and welded stainless steel pipes. It is mainly used in buildings such as factories, bridges and ships. Structures and pipelines for general transport fluids. Such steels are generally used without heat treatment.
(3) Low alloy high strength structural steel (GB/T1591-1994)
In addition to containing a certain amount of basic elements of silicon or manganese, such steels also contain other elements that are suitable for China's resources, such as vanadium (V), niobium (Nb), titanium (Ti), aluminum (Al), molybdenum (Mo). , nitrogen (N), and rare earth (RE) and other trace elements. According to the chemical composition and performance requirements, its grades from Q295A, B, Q345A, B, C, D, E, Q390A, B, C, D, E, Q420A , B, C, D, E, Q460C, D, E and other steel grades, its meaning with carbon structural steel.
V, Nb, Ti, Al, etc. refine the grain microelements. In addition to Class A and Class B steels in such steels, Class C, Grade D, Grade E steels should contain at least one of them; in order to improve the properties of steels. A, B grade steel can also be added to one of them. In addition, the residual element content of Cr, Ni, and Cu in this type of steel is not more than 0.30%. Q345A, B, C, D, E are representative of such steel. Grades, which A, B grade steel is usually called 16Mn; C grade above steel need to add more than one trace element, its mechanical properties to increase a low-temperature impact performance.
Compared with carbon structural steel, this type of steel has advantages of high strength, good comprehensive performance, long service life, wide application range, and comparative economic advantages. The steel is rolled into plates, profiles, and seamless steel tubes, etc., and is widely used. Bridges, ships, boilers, vehicles and important building structures.
(4) Alloy Structural Steel (GB/T3077-1999)
This type of steel is based on high-quality carbon structural steel, and appropriate addition of one or more alloying elements is used to improve the mechanical properties, toughness, and hardenability of the steel. Products made of this kind of steel usually undergo heat treatment. (normalizing or quenching); the parts and components made of them must be subjected to quenching or surface chemical treatment (carburizing, nitriding, etc.), surface hardening, or high-frequency quenching prior to use. The composition (mainly carbon content), heat treatment process and use of different, this type of steel can be roughly divided into carburizing, quenching and nitriding steel three.
This kind of steel multi-rolling (forging) made round, square, flat profiles and seamless steel pipe, used in the production of mechanical products more important and larger size of the zero, parts and high-pressure pipes, containers, etc., this high-quality carbon structural steel More excellent comprehensive mechanical properties.
This type of steel seamless steel pipe is widely used in hydraulic props, high pressure gas cylinders, high pressure boilers, fertilizer equipment, petroleum cracking, automotive axle bushings, diesel engines, hydraulic pipe fittings, etc.
(5) Stainless Steel (GB/T1220-92, GB/T1221-92)
According to the main industrial application, stainless steel tube is divided into two major categories: stainless acid-resistant steel and heat-resistant steel.
A, stainless acid-resistant steel is divided into two kinds of stainless steel and acid-resistant steel. In the air can resist corrosion of steel called stainless steel; in a variety of aggressive media, corrosion resistance of steel called acid-resistant steel. Stainless steel is not necessarily Acid corrosion, but acid-resistant steel has a good stainless performance.
In addition to the five major elements (C, Si, Mn, P, S), this type of steel mainly contains chromium, nickel alloy elements such as chromium steel (Cr13 type), chromium nickel steel (18-8 type); also in the chromium Nickel based on molybdenum, niobium, titanium, nitrogen and other elements in one or more.
Such steel-made rounds, plates, belts, wires, tubes, etc. are widely used in chemical equipment, medical equipment, food industry equipment, home kitchens, hotels, and restaurants.
B, heat-resistant steel can not afford to be divided into heat-resistant and can not afford two kinds of steel. In the high temperature resistant to media corrosion without skin from the steel called steel; at high temperatures resistant to media erosion and have sufficient strength The non-leather steel is called heat-resistant steel.
This type of steel contains one or more of alloying elements such as aluminum (Al), tungsten (W), cobalt (Co), and vanadium (V), in addition to chromium and nickel elements in stainless acid-resistant steel. Manufacturing of rounds, plates, belts, pipes, etc. are widely used in petrochemical equipment, power station boilers, gas turbines and industrial furnace components and components working at high temperatures.
The stainless steel tube classification information comes from

UNI Flanges

UNI style of flanges:
Plate (UNI 2276 2277 2278 6083 6084) ,Blind (UNI6091 6092 6093 6094 6095 6096 6097) ,Threaded (UNI2253 2254), Welding-Neck (UNI2280 2281 2282 2283 2284 2285 2286)
Pressure rating:
PN 6 PN10 PN16 PN25 PN40 PN64 PN100

Features

Dimensions:
UNI AND DRAWING
Carbon Steel Materials:
ASTMA105-ASTMA350LF2/ASTMA694 F42-F52-F60-F65-70/C22.8/C21/Rst37.2/S235JRG2/P355NH/SS400
Alloy Steel Materials:
ASTM A182 F1-F11-F12-F22-F5-F9-F91
Stainless Steel Materials:
ASTM A 182 F304/304L/304H-ASTM A182 F321/321H-ASTM A182 F347-347H-ASTM A182 F316-316L-316H
Special alloys:
DUPLEX-SUPER DUPLEX-INCONEL-INCOLOY-MONEL-HASTELLOY-TITANIUM

UNI Flanges,UNI Blind Flanges,UNI EN Flanges,Flat Faced Flange

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