Will a stainless steel thermos flask rust? Can I continue to use the rusted stainless steel after cleaning it?

In the many replies to the articles published by the editor, many friends have raised the question of "Will stainless steel thermos flasks rust?". http://www.umbottle.com/ProductsDetail-OS-10039.htmlDo some friends think that those who raise these questions are obviously inexplicable? How can a stainless steel thermos flask made of stainless steel rust? Can it still be called stainless steel if it rusts?

Friends who hold different opinions above, I want to say that they are all correct. Why do I say that? If the stainless steel thermos cup is produced according to the standard and qualified 304 stainless steel and 316 stainless steel are used, it will not rust. http://www.umbottle.com/ProductsDetail-OS-10039.htmlHowever, if the material used by the manufacturer is not qualified and the production is not standardized, then the stainless steel thermos cup will rust.

The reasons for the rust of stainless steel thermos cups are as follows:

1. The material does not meet the standard. 201 stainless steel is used. The corrosion resistance of 201 stainless steel is lower than that of 304 stainless steel and 316 stainless steel, and 201 stainless steel is not a food grade material. 201 stainless steel water cups will still rust after a period of use, especially when the water cups are used to hold carbonated beverages. http://www.umbottle.com/ProductsDetail-OS-10039.htmlSecondly, 304 stainless steel and 316 stainless steel that do not fully meet the standard are also likely to rust.

2. Irregular production. Even if qualified stainless steel materials are used, if the welding and temperature processes are not properly controlled during production, resulting in excessive welding temperatures and material oxidation, coupled with incomplete polishing and electrolysis in the later stage, the stainless steel water cup will also rust. This is easy to judge. http://www.umbottle.com/ProductsDetail-OS-10039.htmlFriends can take a look at the stainless steel water cup you use, clean and dry it, and observe whether there are black welding points or lines at the welding position of the inner wall of the water cup. If there are, it means that the welding position of the thermos cup you use has been oxidized and rusted due to inadequate production control.

Can I continue to use a stainless steel water cup after cleaning the rusted parts?

This first depends on the location of the rust, and secondly on the extent of the rust. Finally, after cleaning, observe for a few days to see if any rust still occurs.

The locations where stainless steel thermos bottles rust vary. Some of them are caused by high salt content in the environment, which causes rust on the surface of the water cup. http://www.umbottle.com/ProductsDetail-OS-10039.htmlIf the salt content is too high and the surface of the water cup rusts, it does not mean that the outer shell of the water cup must be made of 201 stainless steel. The water cup factory usually performs salt spray tests on incoming materials.

At present, it is to test whether the corrosion resistance of the material meets the standard. Since it is external rust, if it is found that it does not damage the production function after cleaning, it can still be used. http://www.umbottle.com/ProductsDetail-OS-10039.htmlAs mentioned earlier, it may be that the welding line on the inner wall of the inner tank is oxidized due to irregular production. If the oxidation black spots or black lines are not eliminated after cleaning, it is recommended not to continue using such a water cup.