There is a situation in the market where 304 or ordinary stainless steel is used to imitate 2205 duplex stainless steel plates. Users can effectively distinguish the authenticity through two methods: material testing and interpretation of the quality guarantee certificate.
In terms of material testing, the most reliable method is to use a spectrometer to detect the chemical composition. The key element content range for 2205 duplex steel is: chromium 22.0% - 23.0%, nickel 4.5% - 6.5%, molybdenum 3.0% - 3.5%, and nitrogen 0.14% - 0.20%. If the molybdenum content is lower than 3.0% or the nitrogen content is significantly lower, it may be a counterfeit product. Additionally, the magnetic method can be used as an auxiliary judgment - 2205 duplex steel contains approximately 50% ferrite and has medium magnetism, while 304 stainless steel has basically no magnetism or very weak magnetism. More professional testing includes observation of the metallographic structure, and 2205 duplex steel should have a uniform duplex structure, with ferrite and austenite each accounting for approximately 50%.
Interpreting the warranty certificate is another important method for identifying authenticity. A genuine warranty certificate should contain the following information: the manufacturer's name, the applicable standard (such as ASTM A240 or GB/T 24511), the furnace batch number, the measured values of chemical composition, the measured values of mechanical properties (yield strength, tensile strength, elongation, etc.), and the official seal. Users should verify whether the measured data in the warranty certificate meets the standard requirements and pay attention to whether the furnace batch number in the warranty certificate is consistent with that on the actual product. It is recommended to request the supplier to provide the original factory warranty certificate instead of a self-printed copy.
For large-scale purchases or critical applications, it is recommended to entrust a qualified third-party testing institution to conduct re-inspection to ensure the authenticity and reliability of the materials.
Jiangsu Cunrui Metal Products Co., Ltd. The 2205 duplex stainless steel plates we supply are all of genuine quality. We will provide the original factory warranty certificate with the goods, and we also support customers in having the products re-inspected and verified by a third-party testing institution.
If you need any assistance, please feel free to contact our company at any time. We will be more than happy to offer you high-quality products and services.