304 stainless steel plate products have strong corrosion resistance, for ordinary alkali solutions and organic acids, inorganic acids have good corrosion resistance, it is a high alloy steel, can resist corrosion in air or chemically aggressive media. Stainless steel has an aesthetically pleasing surface and good corrosion resistance. It does not require surface treatments such as electroplating to give stainless steel full surface properties. An aspect of steel, often referred to as stainless steel.
What aspects of 304 stainless steel pipe need to be paid attention to when welding?
1. In the welding process, the bottom layer and the cladding layer are treated needle valve manufacturer differently, and the welding data applicable to each is sel ected to weld.
2. In order to ensure the corrosion resistance of the cladding, the weld composition of the cladding should be as similar as the composition of the cladding steel as much as possible.
3. At the junction of the two layers, in order to avoid the overlay from being diluted by the bottom layer and reduce the corrosion resistance, the key to welding is to deal with the welding of the two layers of the border, and the transition layer weld can be set between the bottom layer and the cladding layer.
4. Post-weld heat treatment Regarding the welding components of large thickness stainless steel wrenches, post-welding heat treatment can eliminate the residual stress of welding.
5. It should be noted that when the heat treatment temperature is depressed, the iron cable body will be decarbonized on the side of the carbon steel, so that the progress is reduced; On the side of the stainless steel, it is carburized and hardened and brittle, forming a reduced impact toughness and becoming a danger of welded joint failure, which is not advisable.
The use of stainless steel pipe is now more and more extensive, because of its good corrosion resistance in the construction of the project has played a vital role, in the production process we need to carry out solid solution treatment of stainless steel pipe, the main purpose is to obtain a certain martensitic so that the hardness of the product increases, let's take a look at the solution treatment of stainless steel pipes:
(1) The intermediate aging method is reheated to (760±15) °C after the solid solution treatment, and the insulation is 90min due to the precipitation of Cr23C6 carbide from the austenite, which reduces the carbon and alloying element content in the austenitic 904L stainless steel tube, so that the Ms point is raised to 70 °C and then cooled to room temperature to obtain martensite + α ferrite + residual austenite tissue, and the residual austenite is decomposed at the subsequent 510 °C.
(2) High temperature adjustment and cryogenic treatment method after solid solution first heating to 950 °C insulation for 90min, due to the increase of Ms point, cooling to room temperature can obtain a small amount of martensitic; After 12 needle valve that, a certain amount of martensitics can be obtained by cold treatment at -70 °C for 8h.
(3) After the cold deformation method of solid solution treatment, the cold deformation at room temperature, the number of martensitics formed by the 904L seamless tube during the cold deformation is related to the amount of deformation and the composition of the 904L stainless steel tube.