304 thin-walled stainless steel pipes have excellent corrosion resistance, high hardness, high temperature resistance and other properties, and are widely used in food, industry, chemical industry, etc. However, as a common and general metal material, 304 stainless steel pipes are not omnipotent, and they cannot be used in any environment. They still have extreme conditions for use.
In terms of corrosion resistance, high temperature resistance, and hardness, the limit of the use conditions of 304 thin-walled stainless steel pipes is naturally much stronger than 201 stainless steel pipes in terms of rust resistance. However, in a strong acid environment, the corrosion resistance of 304 stainless steel pipes will also be greatly weakened. For example, in coastal cities, the air has a high salt content and chloride ions, so 304 stainless steel pipes may not be applicable, and 316 stainless steel is required.
304 stainless steel pipe has strong high temperature resistance, but the test shows that the use temperature of 304 stainless steel pipe cannot be higher than 650 degrees. Many people say that 304 stainless steel pipe can withstand the high temperature of 800 degrees, which is incorrect. If it exceeds this temperature, 304 thin-walled stainless steel pipes will have problems. This is because the heavy metals in the material will precipitate when the temperature exceeds this temperature, and the tensile strength, hardness, and yield strength of the steel pipe are all decreasing.
Finally, the hardness of 304 stainless steel pipe is very high, and the safety of stainless steel welded pipe made of it is still quite high. It cannot be bent or otherwise processed by heat treatment, but can only be processed by cold treatment, which is our common use of machinery and equipment for processing, such as bending, pressing into oval tubes, or other shapes of special-shaped tubes.
However, the bending and special-shaped processing of 304 thin-walled stainless steel pipes are not unlimited operations. After testing, the tensile strength of 304 stainless steel pipes is about 550MPa, and its hardness is about 150~160HB, and we cannot exceed this limit when processing. At the same time, we need to pay attention to the fact that the protective layer on the surface of the stainless steel pipe will be destroyed after cold processing, and the corrosion resistance will decrease; after cold treatment and stretching, the surface of the stretched pipe will become thinner, and its toughness will naturally decrease significantly. Therefore, a limit value should also be considered during processing.
The above is the bearing limit of 304 thin-walled stainless steel pipes. Although 304 stainless steel pipe has good high temperature resistance, corrosion resistance, and high hardness, it is recommended to use 310s or 316 when it is used at temperatures above 600℃; it is recommended to use 316 or 316l when it is used in an environment with chloride ion corrosion. In addition, it should be noted that the corrosion resistance of 304 thin-walled stainless steel pipe will decrease after bending and extrusion; the toughness will decrease after stretching. Therefore, when processing 304 stainless steel welded pipe, its limit value needs to be considered.
Post time: Apr-28-2025