In addition to common scenes in life， stainless steel is also used in some high-end machinery fields， such as food industry， chemistry， medical devices， aircraft exhaust pipes
7Air pressure and water pressure test: conduct water pressure test for pressure resistant pipes one by one，Stainless steel square tube and keep it for no less than seconds at the specified pressure value. The water pressure test of conventional supply is MPa. The air pressure test is p = .mpaa.
wAustenitic stainless steel has good resistance to uniform corrosion，316L stainless steel decorative pipeTechnology of smelting waste residue 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 ~ ℃ 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 CrC 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.
According to the purpose， it is mainly divided into oil well pipe (casing， pipeline pipe， boiler pipe， mechanical structure pipe， hydraulic prop pipe，Stainless steel square tube gas cylinder pipe， geological pipe， chemical pipe (high-pressure fertilizer pipe， petroleum cracking pipe) and marine pipe. Calculation formula for weight of stainless steel square tube: (nozzle perimeter - actual thickness) actual thickness is .， of which . is a constant converted from stainless steel density.
AHelisanThere are ba face， b face， (white skin)， D face， (frosted)， HL (wire drawing)，Stainless steel square tube K face and other surfaces with good quality and brightness.
KnThe internal and external greasy dirt and sundries at the pipe end shall be completely removed to keep the pipe inside the pipe fittings clean.
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，316L stainless steel decorative pipeTechnology of smelting waste residue 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 ℃ (mpa ℃ (mpa) for h; when the temperature condition increases to ℃ (the stress decreases to MPa)， 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 ℃ (the temperature creep rate of mpa stainless steel pipe sample increased to ℃ (mpa steady-state creep rate reaches the maximum value under several test conditions， the material maintains a low level of creep rate. Under ℃ MPa， s creep deformation rate does not increase， which shows that it is not very sensitive to the temperature and stress Compared with other common nuclear power 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 hours of test， the total strain does not exceed .%. The curve is relatively stable with small fluctuation，tisco stainless steel sheet,taigang stainless steel sheet,stainless steel sheet,stainless steel coil,stainless steel strip,stainless steel tube-TISCO Stainless Steel Co.,Ltd indicating that the test data is stable and reliable. Stainless steel pipes have 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 increases with the increase of Cr content. However， stainless steel pipes In the subsequent heat treatment process， 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， and make the electrode potential of stainless steel pipe Therefore， in order to obtain good corrosion and wear resistance， some scholars change the corrosion resistance of stainless steel pipes through heat treatment， and study the effects of austenitizing temperature and time， tempering temperature and time on stainless steel It is found that the austenitizing temperature can change the mechanical properties， but has little effect on the corrosion properties， while the tempering temperature has a great effect on the corrosion resistance of the material through the influence on the second phase. The corrosion wear resistance can be improved through appropriate austenitizing temperature and return fire temperature. Some scholars use surface treatment to improve the corrosion resistance of the material It is concluded that low-temperature nitriding forms a diffusion layer on the surface of the material， improves the wear resistance of the material， acts with Cr and chemically stable phase -fen to improve the corrosion resistance of the material.
(VI) the growth rate of fixed asset investment in the iron and steel industry dropped significantly. From to June， the investment in fixed assets in the iron and steel industry was . billion yuan， a year-on-year increase of % of which the investment in ferrous metal smelting and rolling was . billion yuan， down percentage point from the same period in ; The investment in ferrous metal mining and dressing was . billion yuan a year-on-year increase of %， a year-on-year increase of %， and the growth rate fell sharply by percentage points.
lInspection: after crimping， check the crimping size with a special gauge.
TOxygen plus gas flame can not cut stainless steel plate because stainless steel is not easy to be oxidized.
TInspection itemsThe surface of the steel strip in the state of supply shall be rough or bright.
hHThe large electric clamping tool is V power supply， and the motor drives the oil cylinder to clamp. The connecting oil pipe and quick connector must not be contaminated， otherwise the dirt entering the oil circuit system will affect the normal use of the tool. Connect the main engine and hydraulic cylinder， turn on the power supply first， then tighten the pressure relief valve， wait until the pressure gauge rises to about MPa， or the main engine automatically trips， then open the pressure relief valve， turn off the power supply， and remove the tong head after complete pressure relief.
As long as it is a socket connected stainless steel wire buttress must be set through calculation.
· Pulp and paper industry classifier， bleaching equipment， storage and treatment system.
querydThe 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.
VStainless steel seamless steel pipe for fluid transportation (instead of gbt- instead of gbt- instead of gb-)
Seamless stainless steel pipe， also known as stainless steel pipe， is made of steel ingot or solid pipe blank through perforation， and then made by hot rolling， cold rolling or cold drawing. The specification of seamless steel pipe is expressed by outer diameter * wall thickness mm. With the implementation of Chinas reform and opening-up policy， 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， a common pipe， will gradually withdraw from the historical stage under the influence of relevant national policies because of its corrosiveness. Plastic pipe， composite pipe and copper pipe have become common pipes in the pipeline system. However， stainless steel pipe has more advantages， especially the stainless steel pipe with wall thickness of only . ~ mm， which has the characteristics of safety， reliability， sanitation， environmental protection， economy and applicability in high-quality drinking water system， hot water system and water supply system that puts safety and sanitation first. 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 peoples living standards.
sOrganic substances (such as melons and vegetables， noodle soup， phlegm， etc.) adhered to the surface of stainless steel constitute organic acids in the presence of water and oxygen. For a long time， the corrosion of organic acids on the metal surface.
pJPhysical properties the total heat transfer coefficient of metal depends not only on the thermal conductivity of metal， but also on other factors. In most cases， rust scale and the surface condition of metal. Stainless steel can keep the surface clean， so its heat transfer is better than other metals with higher thermal conductivity. Liaocheng Suntory stainless steel provides the technical standard of stainless steel plate Stainless steel plate high-strength stainless steel plate with excellent corrosion resistance， bending workability， toughness of welding parts and stamping workability of welding parts. Specifically， Si， Mn， P， s， less than .% of N， more than % of Cr and less than % shall meet & le; Cr Mo Si & le; & le; Ni (c n) . (Mn Cu) & le; Cr . (Ni Cu) Mo & Ge; ， . & le; C， and then cooled at a cooling rate of more than ℃ / S. in this way， it can become a high-strength stainless steel plate with martensite content of more than %， high strength of more than mpa， corrosion resistance and bending processability， and excellent toughness of welding heat affected zone. It can be significantly improved by reusing Mo， B， etc High stamping performance of welded parts.
Density & rdquo; Density of series: s， S and density stainless steel coils of are divided into Austenitic， ferrite， martensite， duplex (ferrite austenite) stainless steel cold rolled coil and stainless steel hot rolled coil.