The most commonly used decorative tube sheet is that austenitic stainless steel 304 material is generally non-magnetic or weakly magnetic, but the magnetic properties of smelting or processing caused by fluctuations in chemical composition may also occur, but this cannot be considered as counterfeit or unqualified. , stainless steel screw manufacturers tell you what is the reason?
As mentioned above, austenite is non-magnetic or weakly magnetic, while martensite or ferrite is magnetic. A small amount of martensite or ferrite may be formed in the austenitic 304 stainless steel due to segregation during smelting or improper heat treatment. Thus, 304 stainless steel will have a weak magnetic field.
In addition, the cold-processed microstructure of 304 stainless steel will also be transformed into martensite. The greater the degree of cold work deformation, the greater the martensitic transformation and the greater the magnetic properties of the steel. Like a batch of steel strips, it produces 76 tubes with no obvious magnetic sensation and produces 9.5 tubes. Due to the large magnetic deformation of the cold bending deformation, the manufacturer's rectangular tube is larger than the round tube, especially the angle steel section. The shape is stronger and more magnetic.
In order to completely eliminate the magnetic properties of 304 steel caused by the above reasons, stable austenite can be restored by high temperature solution treatment to eliminate magnetic properties. In particular, the magnetic properties of 304 stainless steel due to the above reasons are different from those of other materials (such as 430 and carbon steel), that is, the magnetic properties of 304 steel always exhibit weak magnetic properties.
Stainless steel screw manufacturers tell us that if the stainless steel strip is weakly magnetic or fully magnetic, it should be judged as 304 or 316 material. If it is magnetically identical to carbon steel, it exhibits strong magnetic properties because the difference is not 304 material.
29. How to prevent the stainless steel screws from locking?
The problem of locking the stainless steel screw is one of the problems encountered during the use of the screw. How to solve the problem of locking the stainless steel screw,
1. When selecting the stainless steel nut used with the stainless steel screw, you must select the matching connector product.
2. The degree of tensile strength of the stainless steel screw and the load of the matching nut must meet the mechanical properties of the object to be used.
2, when using stainless steel screws, pay attention to check whether the screw thread is complete, whether there are residues or stains.
3, can be used to lubricate the fasteners before use. It is recommended to use butter, molybdenum disulfide, mica, graphite or talcum powder for lubrication. At present, it is commonly used to do lubrication to prevent lockup.
4. Do not operate the stainless steel screws too fast and the strength of the operation should not be too large.
5, the use of gaskets can effectively prevent the problem of over-tightening.