·Cargo box of ship or truck & middot; Food processing equipment standard ASTM / ASME......... A240 UNS S3 / s31803euronorm......... 4462 x2crnimon 23afnor.................. Z3 CrNi 205 azdin.............................. W. NR 4462 corrosion resistance uniform corrosion due to chromium content (22%), linear coefficient, thermal conductivity, quality, hot melt and magnetism of stainless steel pipe will change greatly at low temperature. Resistance, line coefficient decreases at low temperature; The thermal conductivity and mass heat capacity decrease sharply at low temperature; Young's modulus (longitudinal modulus) increases when the temperature decreases. Because the austenitic series stainless steel pipe has MS point (martensite start temperature or martensite formation temperature) at low temperature (subzreo temperature), martensite can be formed when it is kept below MS point. The formation of martensite at low temperature makes the representative steel sus (18Cr-8Ni) of austenitic stainless steel non-magnetic at room temperature and magnetic at low temperature.
.Austenitic stainless steel has good resistance to uniform corrosion, but there are still the following problems in local corrosion resistance: intergranular corrosion of austenitic stainless steel. Austenitic stainless steel will have intergranular corrosion when it is kept warm at 450 ~ 850 ℃ or cooled slowly. The higher the carbon content, the greater the tendency of intergranular corrosion. In addition, intergranular corrosion also occurs in the heat affected zone of the weldment. This is due to the precipitation of Cr rich Cr23C6 on the grain boundary. The chromium poor area is formed in the surrounding matrix, which is caused by corrosion of the primary cell. This intergranular corrosion phenomenon also exists in the ferritic stainless steel mentioned above.
Steel strip material: different steel strip materials determine the quality of stainless steel, which is a major factor affecting the price of stainless steel at present.
.Stainless welded pipe (grade y) gb3280-84 stainless cold plate (grade I)
5 identification number and indication use international chemical element symbols and national symbols to indicate chemical composition. For a long time, stainless steel plate, excellent quality and favorable price. Use letters to indicate composition content: for example stainless steel belt and stainless steel pipe have complete products, China and Russia use fixed digits to indicate steel series or numbers; for example, the United States, Japan, 300 series, 400 series 200 series; the serial number is composed of Latin letters and order, which only indicates the purpose.
The best choice is also frequently launched in the market. If you want to buy a stainless steel water supply pipe with quality assurance, how should you choose?
It has excellent stress corrosion cracking resistance. Even duplex stainless steel with low alloy content has higher stress corrosion cracking resistance than austenitic stainless steel,Stainless steel rusty, especially in the environment containing chloride ions. Stress corrosion is a prominent problem that ordinary austenitic stainless steel is difficult to solve.
The corrosion resistance is the same, and the strength is better because the carbon content is relatively high.
Prepare materials and tools, prepare corresponding materials and tools and check whether they match and apply.
Recommendation and consultation.Buttress shall be set at the turning of T-interface pipeline in vertical or horizontal direction. The size of buttress shall be determined through calculation according to pipe diameter, corner, working pressure and other factors.
The pipes for pipe cutting shall be professionally cut by stainless steel. Rotate it for two circles, then slightly tighten the piece, and then rotate it for two circles until it is cut off. It must not be enough to allow personal strength to be in place at one time to lock the piece to cut off the pipe, otherwise the pipe end will be cut off, and the pipe fittings or rubber rings cannot be inserted; After the pipe above DN65 is cut, the internal and external burrs must be removed with a hand grinder, and an appropriate outer slope opening shall be opened at the same time to avoid damaging the sealing ring.
Seamless stainless steel pipe also known as stainless steel pipe, cold rolling or cold drawing. The specification of seamless steel pipe is expressed by outer diameter * wall thickness mm. With the implementation of China's reform and opening up, the national economy has achieved rapid growth, and a large number of urban houses, public buildings and tourism facilities have been built, which puts forward new requirements for hot water supply and domestic water supply. In particular, people pay more and more attention to the problem of water quality, and the requirements are also increasing. Galvanized steel pipe, will gradually withdraw from the historical stage under the influence of relevant countries because of its corrosivity. Plastic pipe, composite pipe and copper pipe have become common pipes in the pipeline system. However, under certain circumstances, stainless steel pipe has more advantages especially the stainless steel pipe with wall thickness of only 0.6 ~ 2mm. In high-quality drinking water system, it has the characteristics of safety hot water system and water supply system that puts safety and sanitation first,Stainless steel pipe, reliability, sanitation, environmental protection, economy and applicability. It has been proved by engineering practice at home and abroad that it is one of the new, energy-saving and environmental protection pipes with good comprehensive performance of water supply system. It is also a very competitive water supply pipe, which will play an incomparable role in improving water quality and people's living standards.
total cost.Logistics cost: different delivery locations determine different transportation costs. The long-distance transportation cost should be 500 yuan per ton and the short-distance transportation cost should be about 300 yuan per ton.
Hardness test: annealed stainless steel pipes with inner diameter of more than 0mm and wall thickness of less than 13mm can be tested by w-b75 Vickers hardness tester, which is very fast and simple, and is suitable for rapid and nondestructive qualification test of stainless steel pipes. For stainless steel pipes with inner diameter of more than 30mm and wall thickness of more than 2mm, Rockwell hardness tester shall be used to test HRC hardness. Stainless steel pipes For stainless steel pipes with inner diameter greater than 30mm and wall thickness less than 2mm, the surface Rockwell hardness tester shall be used to test HRT or hrn hardness. For stainless steel pipes with inner diameter less than 0mm and greater than 8mm, the special Rockwell hardness tester for pipes shall be used to test hr15t hardness. When the inner diameter of stainless steel pipes is greater than 26mm, the Rockwell or surface Rockwell hardness tester can also be used to test the hardness of pipes.
(VI) the growth rate of fixed asset investment in the iron and steel industry dropped significantly. From 2013 to June, the investment in fixed assets in the iron and steel industry was 303.5 billion yuan, a year-on-year increase of 3%, of which the investment in ferrous metal smelting and rolling was 235.6 billion yuan, a year-on-year increase of 3%,Stainless steel wire drawing tube, down 1 percentage point from the same period in 2012; The investment in ferrous metal mining and dressing was 67.9 billion yuan, a year-on-year increase of 8%, and the growth rate fell sharply by 15 percentage points.
.The content of chromium, molybdenum and nitrogen in local corrosion-resistant duplex stainless steel makes it have strong ability to spot corrosion and interstitial corrosion in oxidizing and acidic solutions.
The selection of stainless steel plate shall consider the operating conditions, such as manual operation or automatic operation, the performance and type of hot press, and the quality requirements for materials, such as hardness, gloss, etc. Economic accounting should also be considered. Each time the steel plate is newly polished, it is required to produce a number of decorative plates with slow quality.
The requirements for weldability and weldability vary from product to product. A tableware usually does not need welding performance, and even includes some pot enterprises. However, most products require good welding performance of raw materials, such as class II tableware, thermos cup, steel pipe, water heater, water dispenser, etc.