◆ stainless steel and alloy tool steel (C content is expressed in thousandths), such as 1 thousandth of 1Cr18Ni9 (i.e., stainless C & LE); 0.08%, ultra low carbon C & le; 0.03% if the international stainless steel mark, the American Iron and Steel Institute uses three digits to mark various standard grades of malleable stainless steel. Among them, austenitic stainless steel is indicated by numbers of 200 and 300 series, and ferritic and martensitic stainless steel is indicated by numbers of 400 series. For example, some common austenitic stainless steels are marked with 20, 30, 316 and 310, martensitic stainless steels are marked with 4420 and 440C, duplex (austenitic ferrite), stainless steels, precipitation hardening stainless steels and high alloys with iron content less than 50% are usually named by patent name or trademark.
The main function of chromium is the organizational structure of. Chromium has high chemical stability, isolate the metal from the outside, the corrosion resistance decreases.
.Brinell hardness in stainless steel pipe standards, Brinell hardness is widely used, and the hardness of the material is often expressed by indentation diameter, with high temperature strength and high temperature plasticity the nickel content of some models of austenitic stainless steel must be slightly higher than that shown in the table; optional High TA content is 0.10%; high content is 0.75%; high content is the basic characteristics of stainless steel it is not suitable for steel pipes with hard or thin steel.
347h chemical composition carbon C: Manganese Mn: silicon Si: chromium Cr: nickel Ni: phosphorus P: sulfur s: niobium NB: 347h stainless steel Name: austenitic stainless steel standard: aisastm model: 347huns No.: Note: a single value is a high value unless otherwise indicated; when used in some pipe making processes, excellent oxidation resistance and corrosion resistance, good structural stability, uniform chemical composition, good processing performance and welding performance, high dimensional accuracy and surface quality. 5 causes of rust when brown spots appear on the surface of stainless steel They were greatly surprised: & rdquo; stainless steel will not rust. Rust is not stainless steel. There may be something wrong with the steel quality. & rdquo; in fact, this is a one-sided wrong view of the lack of understanding of stainless steel. Stainless steel will also rust under certain conditions
.It is a kind of product manufacturing enterprise. It has long been specialized in L stainless steel pipe, s stainless steel pipe and 904L stainless steel pipe. Therefore, the specification of a group of slightly larger formed pipes used in the production of pipe molds is about 6000-20000.
According to the specification, the specification of stainless steel pipe is mainly based on gb14975-94 stainless steel seamless steel pipe. The general length (indefinite length) of precision stainless steel pipe and thick wall pipe is 5-10m for hot-rolled steel pipe and 1m or more for hot-rolled steel pipe. The wall thickness of cold drawn (rolled) stainless steel pipe is 0.5-0mm and the length is 0-7m; the wall thickness of stainless steel pipe is greater than 0mm and the length is 5-8m.
The steady creep rate is usually used to evaluate the long-time creep performance of materials. For the application of long-life materials, the steady-state creep rate of stainless steel pipe under high temperature and stress is the key index of the material, and can be extrapolated. The following are the test results of stainless steel pipe under different test conditions. The results show that the steady-state creep rate of stainless steel pipe sample is in the order of magnitude after creep at 550 ℃ (90mpa600 ℃ (85mpa) for 500h; when the temperature condition increases to 650 ℃ (the stress decreases to 70MPa), the creep performance of stainless steel pipe sample is good, and the steady-state creep rate is in the order of magnitude; when the temperature further increases to 700 ℃ (the temperature creep rate of 65mpa stainless steel pipe sample increased to 800 ℃ (65mpa steady-state creep rate reaches the maximum value under several test conditions, and creep fracture occurs. See for the change of steady-state creep rate of stainless steel pipe sample under several conditions. When the temperature increases the material maintains a low level of creep rate. Under 650 ℃ 70MPa, s creep deformation rate does not increase, which shows little influence on the temperature and stress, and creep fracture occurs under this condition Compared with several other common structural materials, it can be seen that the creep performance of several materials is better than that of ordinary materials under all test conditions. After 500 hours of test, the total strain does not exceed 0.12%. The curve is relatively stable and the fluctuation is small, indicating that the test data is stable and reliable. Stainless steel pipes are widely used because of their excellent corrosion resistance It is widely used in petrochemical industry, pipeline transportation and other working conditions with strong corrosive media. The main reason for the corrosion resistance of stainless steel pipes is the addition of a large number of elements CrNi, and Cr is the main element determining the corrosion resistance of stainless steel pipes. The electrode potential of stainless steel pipes jumps with the increase of Cr content. However, stainless steel pipes are in the subsequent heat treatment During the treatment, Cr element will precipitate into the matrix in the form of carbide. On the one hand, the hardness of Cr carbide is larger than that of the matrix and the service wear process can improve the wear resistance of stainless steel pipe. On the other hand, the precipitation of Cr containing carbide will lead to Cr Element dilution zone in some parts of the matrix, increase the number of batteries of the material, reduce the electrode potential of stainless steel pipe and reverse the corrosion Therefore, in order to obtain good corrosion and wear resistance, the combination of mechanical properties and corrosion resistance of stainless steel pipe materials needs to be considered. At present, some scholars have studied the effects of austenitizing temperature and time, tempering temperature and time on the mechanical properties of stainless steel pipe by heat treatment to change the corrosion resistance of stainless steel pipe And corrosion resistance, it is found that austenitizing temperature can change mechanical properties, but has little effect on corrosion performance, while tempering temperature has a great effect on the corrosion resistance of materials. Appropriate austenitizing temperature and tempering temperature can improve the corrosion and wear resistance of materials. Some scholars use surface treatment to improve the corrosion and wear resistance of materials, It is concluded that low-temperature nitriding forms a diffusion layer on the surface of the material, improves the wear resistance of the material, interacts with Cr and chemically stable phase 07-fe3n to improve the corrosion resistance of the material.
201 series & mdash; Chromium nickel manganese austenitic stainless steel.
There are three main reasons for oxidation of stainless steel: production process, which is one of the reasons for oxidation of steel products. In terms of production process and product characteristics, forming a thin oxide film on the product surface is the basic process to avoid oxidation, and it is also one of the main characteristics of steel products different from other steel products. It is specialized in products, renewable resources business and business package Including: stainless steel plate, stainless steel coil, stainless steel belt and stainless steel pipe. However, when the oxide film is incomplete and discontinuous due to insufficient or negligent production process, the oxygen in the air will directly react with some elements in the product, resulting in the appearance of oxidation of the product.
The product ground by the grinding belt.
Welcome calls .Hot rolled belt, stainless steel etching belt, stainless steel stretching belt, stainless steel polishing belt, stainless steel soft belt, stainless steel hard belt, stainless steel medium hard belt, stainless steel high temperature resistant belt, etc.
Production process of hot rolled stainless steel strip / coil: 1. Pickling → 2. High temperature rolling → 3. Process → 4. Annealing → 5. Leveling → ⒍ fine cutting → ⒎ packaging → 8. Reach customers.
HL polishing with appropriate particle size abrasive material to make the surface show continuous grinding lines.
Fabrication of stainless steel pipe
Promise and keep promise.While China's exported steel pipes are frequently subject to foreign anti-dumping and countervailing investigations, imported steel pipes are also constantly impacting domestic steel enterprises.
Stainless steel pipe is safe, reliable, hygienic, environmentally friendly, economical and applicable. The successful development of pipeline and new reliable, simple and convenient connection makes it have more irreplaceable advantages of other pipes. It will be used more and more in engineering and the use will be more and more popular. It has a good prospect.
Cold formed alloys can be cut and cold formed. However, due to its high strength and hardness, the alloy needs cold forming more than austenitic steel. Because of its high strength, springback should be fully considered.
.Fabrication of stainless steel pipe
For example, the raw material difference of the three materials, such as 20 and, which are common in the market, is more than 5000 yuan per ton.
D-outer diameter (mm) as stainless steel pipe for reprocessing device, in order to reduce carbon content by vigorously welding chromium carbon compounds at affected parts, or silicon and phosphorus content in Nb steel. In addition, the steel industry with phosphorus content below 0.015% is manufactured. After 20 times of 65% boiling corrosion test, it is found that if the corrosion degree of the solution treated material is less than 0.1mm/a, 650 ℃ & times; The sensitized material for 2h has excellent corrosivity when the corrosion degree is less than 0.2mm/a.