304 food-grade stainless steel water pipe is a very special product. It is difficult to identify the authenticity with just the eyes. The pickling of thin-walled stainless steel water pipes produced in my country is divided into austenite, ferrite, martensite, and other precipitation hardening. Only austenite is Thin-walled stainless steel water pipes that are partially precipitation-hardened and are non-magnetic, so using a “magnet magnet” to distinguish the authenticity of stainless steel water pipes is the wrong method.
Food-grade stainless steel refers to metal materials that comply with the “National Standards of the People’s Republic of China/Hygienic Standards for Stainless Steel Tableware Containers” GB4806.9-2016 and will not dissolve various alloys and harmful substances. In the GB4806.9-2016 standard, the indicators of stainless steel in contact with food are specified in detail. Remember: Food-grade stainless steel is a metal material that complies with the national standard GB4806.9-2016. Generally, the identification methods of 304 stainless steel pipes are:
Magnetic test: 316 stainless steel pipe and 304 stainless steel pipe have low magnetism, and 201 stainless steel pipe has strong magnetism, so those magnets can be tested, but the accuracy is not high, so it is not recommended for everyone to use!
Nitric acid point test: The nitric acid point test for stainless steel pipes is the most intuitive test method to test the corrosion resistance of the substrate. Usually, good 304 stainless steel pipes will only be slightly corroded during the test, while stainless steel pipes with the lowest corrosion and oxidation resistance will, there will be obvious traces of corrosion.
Stainless steel measuring solution: also called stainless steel pipe testing solution. First, make sure there is no stain on the surface of the 304 stainless steel pipe. After grinding off the surface coating, apply a drop of the measuring solution to remove the coating. Observe the color change of the 304 stainless steel pipe in the test area and compare the color of the 304 stainless steel pipe. Or judge by the time it turns red.
Observation through sparks: The sparks and hardness of 304 stainless steel pipes during cutting or welding can also distinguish the quality of stainless steel pipe materials. The above is how to identify the quality of 304 stainless steel pipe.
In addition to the above methods, there are other ways to identify the quality of 304 stainless steel pipes:
Polishing brightness: The brighter the 304 stainless steel pipe, the smoother the surface, and the smaller the oxidized area, the higher the corrosion resistance.
Weld nitrogen protection: Most 304 stainless steel pipes start from the weld, so weld nitrogen protection can effectively improve the corrosion resistance of stainless steel pipes. The stainless steel pipes produced by 304 stainless steel pipe manufacturers do not add nitrogen internal protection, so they are not Recommended for everyone to use!
Precision: Although precision has little to do with the corrosion resistance of 304 stainless steel pipes, the higher the precision of stainless steel pipes, the better the process and the higher the quality.
Post time: May-15-2024