steel stripHow
Stainless steeThe resistance, linear coefficient, thermal conductivity, 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.
The atoms around the gap rearrange with time, resulting in the continuous accumulation of holes, weakening the material, and finally forming macro cracks, resulting in the fracture of stainless steel pipe material. Compared with room temperature, high temperature promotes the accelerated oxidation of materials and the accelerated diffusion of atoms. Under the action of stress, the interaction between internal defects and dislocations can significantly reduce the low cycle fatigue performance of stainless steel tubes. The law of creep deformation of stainless steel pipe can be described by creep curve, which reflects the relationship between deformation and time under specific temperature and stress structure. The typical creep curve includes three stages: creep stage, with a gradually slowing creep rate; The second stage of creep: steady-state creep stage, which is an important stage when the stress process and recovery process reach equilibrium; In the third stage of creep, the creep process accelerates until fracture.
.When the stainless steel pipe with solid core welding wire is prefabricated, the welded junction can usually be rotated for welding, and the ventilation is very easy. At this time, the blocking plate is usually used to block both sides of the welded junction in the pipe, and the bottom welding is carried out for the protection of ventilation (see Table 1) and the outside is blocked with adhesive cloth.
Stainless steel pipe appeared in Foshan, Guangdong Province in the tenth generation of the last century. With the rapid development of science and technology in recent decades, stainless steel pipe production is all over the country. Stainless steel pipe is more and more widely used. But in fact, most people, including many people in the industry, do not know much about the classification and application of stainless steel pipes. Take stainless steel pipe for example.
.Air pressure and water pressure test: conduct water pressure test for pressure resistant pipes one by one, and keep it for no less than 5 seconds at the specified pressure value. The water pressure test of conventional supply is 45MPa. The air pressure test is p = 0.5mpaa.
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, 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, with high temperature strength and high temperature plasticity, 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
Remarks: to ensure the nickel content of stainless steel strip and the mechanical properties of stainless steel strip, material certificate (Baogang material), Japan Nippon Steel Material Certificate (Nippon Steel material) SGS report, etc. can be provided.
(II) The price of steel has been running at a low level. From January 31 to June 2012, the overall performance of the domestic steel market was depressed. With the substantial release of crude steel production capacity, the market supply and demand fell into an imbalance, and the steel price entered a downward channel, which has been weak for more than four months. As of June 26, 2013, the steel price index had dropped to 100.48 points, its advantages are obvious, mainly for its simplicity and low cost, which is suitable for installation on the construction site. However,22 stainless steel, due to its structural characteristics, flux cored welding wire has high requirements for welders during operation, with fast wire feeding speed and high wire feeding accuracy. It is difficult to master. Welders should be specially trained and skilled before they can participate in welding in Yangba, Nanjing And foreign construction sites, we have successfully solved the problem that argon cannot be passed through the junction and repair port.
The shielding gas is argon with a purity of 999%. When the welding current is 50 ~ 50a, the argon flow is 8 ~ 0lmin,7cr17 stainless steel plate, and when the current is 50 ~ 250A, the argon flow is 2 ~ 5lmin.
Where to sell API.1: stainless steel plate: it can be divided into cold-rolled plate and hot-rolled plate. Its surface has bright surface, fog surface and matte surface. It is commonly known as stainless steel plate,2205 stainless steel square pipe, it can also be plated with other light colors according to customer requirements. The main specifications of plates are: 1m * 1m, 1m * 2m, 22m * 44m, 5m * 3M, 5m * 6m. If customer demand is large, we can cut them according to customer size. In addition, we can replace wire drawing plate, anti sliding plate and electroplating plate
Surface treatment difference: surface treatment is usually divided into polishing, wire drawing and wire drawing, and the cost is about 1 yuan and 1 meter. If it is thrown into the lens barrel, the cost per ton will increase by 3000 yuan.
As long as it is a socket connected stainless steel wire, buttress must be set through calculation.
Check the clamping forming effect after each clamping, and there shall be no clamping in place or serious depression of pipe clamping. According to visual inspection, the pipe fitting end and the pipe are tightly bonded. The smaller the diameter of the diamond edge of the pipe fitting above DN25 is slightly smaller than the outer diameter of the pipe, ranging from 0.1-2mm. The larger the pipe diameter, the greater the difference.
how.5: stainless steel wire: it can also be called stainless steel wire, coil rod and coil yuan, but it is different from stainless steel wire rope. Wire rod mainly includes spring wire and screw wire, professional stainless steel plate, stainless steel coil, stainless steel belt, stainless steel pipe and other special products. It is a 20-year-old brand with advantages in price and guaranteed quality. As the name suggests: screw wire is mainly used to make screws, The spring wire is used to make springs or other hardware products required. Others, such as bright wire, hydrogen withdrawal wire, electrolytic wire, axle hairpin wire, etc. the tensile strength is 1500-2000. The hardness of spring wire is as follows: fully soft | 1 / 4 hard | semi hard | 3 / 4 hard | fully hard | extra hard. Steel wire rope gauge: 7 * 1,6 * 127 * 7,7 * 19,17 * 39, etc., which is higher than that of wires, 304 stainless steel is a kind of high alloy steel that can corrode in air or chemical corrosion medium. Stainless steel has beautiful surface and good corrosion resistance. It does not have to go through surface treatment such as color plating, but gives full play to the inherent surface properties of stainless steel. It is used in many aspects of steel, which is usually called stainless steel. Representative properties include 13 chromium steel, 18-8 chromium nickel steel and other high alloy steels.
600 Series & mdash; Martensitic precipitation hardening stainless steel.
Since last year, foreign countries have frequently carried out & ldquo; Double inverse & rdquo; This has a great impact on China's stainless steel casting industry. Export is a large part of the development of China's stainless steel industry and occupies a huge market share in its industrial development. In the face of the current economic downturn and slow development speed, the development of China's stainless steel industry should continuously improve product quality, Better develop overseas trade and deal with trade protectionism combine products with environmental protection, energy resources and cultural environment and improve the competitiveness of stainless steel products. Only in this way can we achieve an invincible position in foreign trade.
.Manufacturing process hot rolling (seamless steel pipe): round tube blank → Heating → Perforation & rarr; Three roll cross rolling, continuous rolling or → Off pipe & rarr; Sizing (or reducing) → Cooling → Straightening & rarr; Hydrostatic test (or flaw detection) → Mark & rarr; The raw material for warehousing and rolling seamless pipe is round pipe blank. The round pipe blank shall be cut and processed by cutting machine, and the blank with a growth of about 1m shall be brought to the furnace for heating. The billet is sent to the furnace for heating at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene. The temperature in the furnace is the key problem. After the round tube billet is discharged from the furnace, it should be pierced through the pressure piercer. Generally, the more common piercer is the cone roll piercer. This piercer has high production efficiency and good product quality. It is specialized in stainless steel plate, stainless steel coil, stainless steel belt and stainless steel pipe, good waterproof performance, fire and high temperature resistance, strong overload capacity, corrosion resistance, radiation protection, long service life, large perforation diameter expansion, and can wear a variety of steel grades. After perforation, continuous rolling or rolling. Take off the pipe after sizing. The conical drill bit of the sizing machine rotates into the steel embryo at high speed to form a steel pipe. The inner diameter of the steel pipe is determined by the outer diameter length of the sizing machine bit. After sizing, the steel pipe enters the cooling tower for water spray cooling. After cooling, the steel pipe will be straightened. After straightening, the steel pipe is sent to the metal flaw detector (or hydrostatic test) for internal flaw detection. If there are cracks, bubbles and other problems inside the steel pipe, they will be detected. Steel pipes should be strictly selected manually after quality inspection. After the steel pipe is inspected the number, specification, production batch number, etc. shall be sprayed with paint. And hoisted into the warehouse by crane.
Han Jianbiao an analyst at Zoomlion steel, pointed out that since, China's steel pipe exports have been only 30000 or 40000 tons per month, of which seamless pipe exports are only about 10000 tons per month.
1 cold rolled oriented silicon steel strip (sheet) represents: 100 times of DQ + iron loss value (at the frequency of 50Hz, the magnetic induction peak with sinusoidal waveform is the unit weight iron loss value of 7T) + 100 times of thickness value. Sometimes G is added after the iron loss value to indicate high magnetic induction. For example, dq133 represents cold-rolled oriented silicon steel strip (sheet) with iron loss value of 3 and thickness of 0.3mm. Now the new model is 30q133.