The rolling of cold drawn (rolled) seamless steel pipe is more complex than that of hot rolled (seamless steel pipe). The first three steps of their production process are basically the same. The difference starts from the fourth step. After the round tube blank is emptied it needs to be started and annealed. After annealing, pickling shall be carried out with special acid. After pickling apply oil. Then it is followed by multi pass cold drawing (cold rolling) and special heat treatment. After heat treatment, it will be straightened.
The application range is wider than that of ferritic stainless steel. Compared with ferritic stainless steel, duplex stainless steel has the following disadvantages: high alloy element content and relatively high price. Generally, ferritic stainless steel does not contain nickel.
.Stainless steel pipe packing bag is nothing more than the function of protecting the surface of stainless steel pipe so most stainless steel pipe users do not have to question this point.
At this time, we usually answer directly: no! What we produce is stainless steel decorative pipe, which belongs to stainless steel slotted pipe. It can not be used as stainless steel water pipe. If you want to choose stainless steel water pipe, you must choose stainless steel pipe.
.In order to obtain seamless pipes with smaller size and better quality, cold rolling, cold drawing or a combination of both must be used. Cold rolling is usually carried out on a two high mill. The steel pipe is rolled in an annular pass composed of variable section circular groove and fixed conical plug. Cold drawing is usually carried out on a single chain or double chain cold drawing machine of 0.5 ~ 100t.
& Ge; about 40 thickness: cold rolled 2B plate (0.09 & mdash; 0mm); hot rolled industrial plate No.1 (3-50mm) medium plate, chemical plate and high temperature plate; width: 5mm --- 850mm steel strip; 1000, 1211250, 1500, 1800 and 2000mm coil plate and flat plate surface: 2B smooth surface, No.1 industrial surface, BA (6K) mirror, 8K mirror, 9K mirror, which is widely used in many media, is better than that of ordinary l austenitic stainless steel, while super duplex stainless steel has very high corrosion resistance. In some media such as acetic acid and formic acid, it can even replace high alloy austenitic stainless steel and even corrosion resistant alloy.
Among the steel products exported by China, steel pipe has always been the focus of foreign anti-dumping and countervailing investigations. The Russian Ministry of industry and trade announced an anti-dumping investigation on China's cold-rolled stainless steel seamless steel pipes exported to the Russian Belarus Kazakhstan customs union. Before that, the Brazilian foreign trade chamber also said that it would impose an anti-dumping tariff of US $743 per ton (about RMB 4748 yuan) on China's steel pipe products, which is valid for five years.
Austenitic stainless steel. It contains more than 18% chromium, about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. Good comprehensive performance and resistance to corrosion of various media.
(III) steel exports grew rapidly. The supply and demand of domestic steel market is unbalanced, and the export of enterprises. From January to June, and 320000 tons of billets and ingots were imported, up 50%. Converting billets into crude steel, the cumulative net export was 25.06 million tons, a year-on-year increase of 13%, accounting for 4% of China's crude steel output. In terms of export price, the average export price of bars and wires from January to June was 623 US dollars per ton, a year-on-year decrease of 18%; US $832 tons of plate, a year-on-year decrease of 8%.
Installation materials.Do a good job of preliminary data research. In the highly competitive market, stainless steel pipe should go deep into the hinterland. It is essential and crucial to do a good job of pre market data research; Only by fully grasping consumer demand trends, habits and other data can we have more confidence to compete for market share. Therefore, the editor of stainless steel pipe believes that in-depth data mining and comprehensive market analysis are powerful for stainless steel control manufacturers in this movement.
Stainless steel has the ability of atmospheric oxidation, that is, it does not rust. At the same time, it also has the ability of corrosion resistance in the medium containing acid, alkali and salt, that is, corrosion resistance. However, its corrosion resistance changes with its own chemical composition, mutual state, service conditions and environmental medium type. For example, 304 has absolutely excellent corrosion resistance in dry and clean atmosphere, but it is moved to In coastal areas, in the sea fog with a lot of salt, it will soon rust, while 316 stainless steel performs well. Therefore, not any kind of stainless steel can resist corrosion and rust at any time
The compressive strength of duplex stainless steel alloy is twice that of austenitic stainless steel. Compared with L and 317L, the designer can reduce its weight. Alloy is especially suitable for & mdash; 50° F/+600° F temperature range, in strict cases (especially for welded structures), it can also be used for lower temperatures. C≤ 0.030 Mn≤ 00 Si≤ 00 p≤ 0.030 S≤ 0.020 CR 20 ～ 20 Ni 5 ～ 5 mo0 ～ 5 n0.14 ～ 0.20 (AUSTENITIC FERRITIC type)
(V) the profitability of the steel plant has declined month by month. In the first half of 2013, the metallurgical industry realized a profit of 73.9 billion yuan, a year-on-year increase of 7%, of which the ferrous metal smelting and rolling processing industry realized a profit of 45.4 billion yuan, a year-on-year increase of 27%. From January to may, the profitability of key large and medium-sized iron and steel enterprises was far lower than the overall level of the industry, and showed a downward trend month by month. Although the profit increased by 34%, it was only 2.8 billion yuan, with a profit margin of 0.19%. In May, 86 key large and medium-sized iron and steel enterprises realized a profit of only 500 million yuan, falling month on month for five consecutive months, of which 34 suffered losses, with a loss surface of 40%.
Home page recommendation.The resistance, linear coefficient, 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.
High frequency welding high frequency welding: with relatively high power supply, it can reach a higher welding speed for steel pipes with different materials, outer diameter and wall thickness. Compared with argon arc welding, it is more than ten times its high welding speed. Therefore, stainless steel pipes for common use have a higher consumption rate. Due to the high speed of high frequency welding, it is difficult to remove burrs in welded pipes. At present, high frequency welding Welded stainless steel pipe can not be borne by chemical and nuclear industries which is also one of the reasons.
7. Distinguish between 316L and 304L. There are two kinds of commonly used stainless steel 30316l (or corresponding to the German / European standard 430844036l, the main difference in chemical composition between 316L and 304 is that 316L contains Mo, and it is generally recognized that 316 has better corrosion resistance than 304 in high temperature environment. Therefore, engineers generally choose 316L parts in high temperature environment. However, there is no absolute thing. In concentrated environment,Stainless steel pipe 316,Stainless steel triangle pipe, 316L should not be used at any higher temperature! No However, this is a big problem. People who study mechanics have all studied threads. Remember a black solid agent that needs to be applied to prevent threads from biting under high temperature: molybdenum disulfide (MOS), from which two conclusions are drawn: No:  Mo is indeed a high resistance material (know what crucible gold is melted in? Molybdenum crucible!).  : molybdenum can easily react with high valence sulfur ions to form sulfide. Therefore, no stainless steel is super corrosion resistant. In the final analysis, stainless steel is a steel with more impurities (but these impurities are more corrosion resistant than steel). If it is steel, it can react with other substances.
.Cold rolled steel strip shall be delivered in the state of heat treatment (annealing, normalizing and tempering after normalizing), and shall be delivered smoothly.
Cold formed alloys can be cut and cold formed. However, due to its high strength and hardness, springback should be fully considered.
Hydraulic saw grinding disc (manual saw wire cutting machine).