Distinguish between authenticity of weathering steel plates
There are many kinds of weathering steel plates, which can be divided into austenite type and martensite or ferrite type according to the arrangement structure at room temperature. The austenite type is nonmagnetic or weakly magnetic, and martensite or ferrite are magnetic. But this is not necessarily the case. If the 304 material is usually used as austenitic decoration tubesheet, generally speaking, is non-magnetic, but because of the exercise composition of chemical composition shake or different processing conditions may also appear magnetic, which can not be considered counterfeit or unqualified. In addition, 304 weathering steel plate will be transformed to martensite after cold working. The greater the deformation degree of cold working, the more martensite transformation, the greater the magnetic properties of steel. On the contrary, the 200 series of weathering steel plates of lower quality are likely to be non-magnetic, so it is wrong to conclude that they are truly weathering steel plates.

People often judge whether they are good or bad by absorbing the weatherproof steel plate. In fact, this is an unrealistic way of distinguishing. It is very likely to suffer from the traditional method of distinguishing the weathering steel plates with magnetism. Weathering steel plate refers to: in the atmosphere and acid, alkali, salt and other corrosive media appear passive, corrosion-resistant and rust-free high chromium (generally 12% ~ 30%) alloy steel. The corrosion resistance of weathering steel plates depends on the alloy elements contained in the steel. The basic alloying elements of weathering steel sheet are nickel, molybdenum, titanium, niobium, copper, nitrogen, etc. to satisfy the requirements of weathering steel sheet arrangement and properties for various uses. Weathering steel plate is simply corroded by chloride ion. As chromium, nickel and chlorine are isotopes, isotopes are exchanged and assimilated to form corrosion resistance steel plate.
In determining the type of weathering steel plate to be selected, the first consideration is the required aesthetic standards, the corrosiveness of the local atmosphere and the selection of finishing criteria. However, other applications are increasingly seeking structural integrity or impermeability. For example, roofs and sidewalls of industrial buildings. In these applications, the cost of the owner's construction may be more important than aesthetics, and the appearance of unclean can also be. The use of 304 weathering steel in a dry indoor environment is quite good.
However, in rural areas and cities, if they want to maintain their appearance in the wild, they often need to be cleaned. In severe polluted industrial areas and coastal areas, the appearance will be very dirty and even rust. However, if we want to get the aesthetic function in the outdoor environment, we need to use nickel bearing weathering steel plates.