Tube selection of electric heating tube

In the design of acid and alkali resistant electric heating tube, the material is very important. Normal acid and alkali use stainless steel, so the corrosion resistance of different grades of stainless steel is also different. Today I will tell you about the stainless steel material. Knowledge.

 304 is versatile stainless steel, which is widely used to make equipment and parts that require good overall performance (corrosion resistance and formability).

301 stainless steel shows obvious work hardening during deformation and is used on various occasions requiring higher strength.

302 stainless steel is essentially a variant of 304 stainless steel with higher carbon content, which can be made to obtain higher strength through cold rolling.

302B is a kind of stainless steel with high silicon content, it has a high resistance to high-temperature oxidation.

303 and 303Se are free-cutting stainless steels containing sulfur and selenium, respectively, and are used in occasions that mainly require free cutting and high surface gloss. 303Se stainless steel is also used to make parts that require hot upsetting because, under such conditions, this stainless steel has good hot workability.

304L is a variant of 304 stainless steel with lower carbon content and is used where welding is required. The lower carbon content minimizes the precipitation of carbides in the heat-affected zone near the weld, and the precipitation of carbides may cause stainless steel to produce intergranular corrosion (welding erosion) in certain environments.

304N is nitrogen-containing stainless steel. Nitrogen is added to increase the strength of the steel.

305 and 384 stainless sheets of steel contain high nickel, and their work hardening rate is low. They are suitable for various occasions that require high cold formability.

308 stainless steel is used to make electrodes.

309, 310, 314 and 330 stainless steel have relatively high nickel and chromium content, in order to improve the oxidation resistance and creep strength of the steel at high temperatures. While 30S5 and 310S are variants of 309 and 310 stainless steel, the difference is that the carbon content is lower in order to minimize the carbides precipitated near the weld. 330 stainless steel has particularly high carburization resistance and thermal shock resistance.

Type 316 and 317 stainless steel contain aluminum, so the resistance to pitting corrosion in marine and chemical industrial environments is much better than that of 304 stainless steel. Among them, the 316 stainless steel variants include low-carbon stainless steel 316L, nitrogen-containing high-strength stainless steel 316N, and free-cutting stainless steel 316F with higher sulfur content.

321, 347, and 348 are stainless steel stabilized with titanium, niobium plus tantalum, and niobium respectively, suitable for welding components used at high temperatures. 348 is a kind of stainless steel suitable for the nuclear power industry and has certain restrictions on the combined amount of tantalum and drill.

         I will introduce you to so many stainless steel materials. In fact, in the design of the electric heating tube, we mainly use stainless steel 304, stainless steel 316, stainless steel 316L, stainless steel 321, etc., and choose different stainless steel materials according to different liquid materials.

Therefore, the choice of the electric heating tube is very important.