7mm304 stainless steel plateWhat is the difference between seasonal and seasonal maintenance

Stainless welded pipe (grade y) gb3280-84 stainless cold plate (grade I)

In the grades of Japanese steel (JIS Series), ordinary structural steel is mainly composed of three parts, which represent the material, such as s (steel) represents steel and f (ferrum) represents iron; The second part represents different shapes, types and uses, such as P (plate) represents plate, t (tube) represents tube, and K (kogu) represents tool; The third part represents the characteristic number, which is generally low tensile strength. For example: SS400 & mdash& mdash; One s represents steel, and the second s represents & ldquo; Structure & rdquo; (structure), 400 is the lower limit tensile strength of 400MPa,2520 stainless steel pipe fittings, and the whole represents ordinary structural steel with tensile strength of 400MPa.

.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.

It is generally suitable for the welding of thin plates below 6mm, with the characteristics of beautiful weld formation and small welding deformation.

.Cutting tool level & rdquo; Martensitic steel, an early stainless steel similar to Brinell high chromium steel. It is also used for surgical tools, which can be made very bright.

2 physical properties chemical composition C: it is specified in, which is usually also called mo2ti or mechanical properties ys (MPA)

Stainless steel capillary material: SUS301 / sus; Inner diameter 4mm-10mm, polished. Purpose of stainless steel capillary: automatic instrument signal tube, automatic instrument wire protection tube; Precision optical ruler circuit, industrial sensor, electronic equipment circuit protection tube; Safety protection of electrical circuit capillary protection of thermal instrument and internal support of air core high-voltage optical cable. Stainless steel capillary characteristics: it has good resistance, high temperature resistance corrosion resistance, wear resistance, tensile resistance, water resistance, and provides excellent electromagnetic shielding performance. Stainless steel hose can be bent into various angles and radius of curvature, and has the same durability and durability in all directions; The stainless steel hose has flexible pitch, and service. It has long been specialized in stainless steel plate, Stainless steel pipe. The axial tension can withstand 6 times of the nominal inner diameter. The yield strength of duplex stainless steel is more than twice that of ordinary austenitic stainless steel. This characteristic makes the designer reduce the weight when designing products, making this alloy more cost-effective than 317L. This alloy is especially suitable for - 50 DEG; F/+600° F temperature range. For applications beyond this temperature range, this alloy can also be considered, but there are some, especially for welded structures& middot;Pressure vessel, high pressure storage tank, high pressure pipeline, heat exchanger (chemical processing industry).

The above conditions can cause corrosion of the protective film on the surface of stainless steel.

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.

　　SPHESPHE—& mdash; Hot rolled steel plate and strip for deep drawing.

Work courses.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.

Steady state creep accelerated oxidation of stainless steel pipe during low cycle fatigue test in air environment. Obvious oxidation will occur in stainless steel pipe. Previous studies have shown that the time required for oxygen in air to diffuse to the fatigue crack tip is about the order of magnitude, and the biochemical reaction time between oxygen and fresh metal is longer than that of oxygen, about 0.015 seconds, which leads to high temperature air When the low cycle fatigue test is carried out in the gas environment, the oxygen content at the fatigue crack tip of the stainless steel pipe sample is always saturated, and the excess oxygen can diffuse to the base, resulting in the weakening of the bonding of the base metal atoms, increasing the embrittlement tendency of the material, and accelerating the expansion and growth of the crack. At the same time of low cycle fatigue, high temperature will also cause creep deformation of the stainless steel pipe, High temperature provides additional energy for the accelerated diffusion of atoms. When there are defects in the material, such as holes, voids, etc., the atomic diffusion becomes easy and with the progress of low cycle fatigue, dislocations will be generated in the material. Under the action of stress, the slip and climb of dislocations interact with point defects to promote the aggregation of micropores and form large holes, such as holes and voids

There are 45 kinds of hot rolled (hot) steel pipes with a diameter of 54 ~ 480mm, 36 kinds of wall thickness of 5 ~ 45mm, such as 1 thousandth of 1Cr18Ni9 (i.e., such as 0Cr18Ni9,316 stainless steel pipe, 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, ferritic stainless steels are marked with 430 and 446, 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.

600 Series & mdash; martensitic precipitation hardening stainless steel pipe.

In conclusion, when calculating the approximate weight of stainless steel pipe and multiplying it by the unit price, the price of 6m stainless steel pipe can be roughly obtained, which can be used in the project budget.

.2 physical properties chemical composition C: it is specified in, which is usually also called mo2ti or mechanical properties ys (MPA)

(VI) the growth rate of fixed asset investment in the iron and steel industry dropped significantly. From 2013 to June, 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%, 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.

In the past few years, the United States has imposed anti-dumping and countervailing duties on a variety of steel pipe products exported from China, rectangular pipe pipeline pipe, welded stainless steel pressure pipe, oil well pipe and seamless steel pipe. These foreign double back pressures have greatly reduced the number of steel pipes exported by China.