Add:No.174, Zhenbei Road, Leyu Town, Zhangjiagang City,Jiangsu, China



Contact:Miss Sarah

Why stainless steel will rust and passivation

Author: ComeFrom: Date:2014-06-28 16:56:32 Hits:919
People often think that magnets and stainless steel to verify the authenticity of their advantages and disadvantages, do not smoke no magnetic, considered good, genuine; absorption is magnetic, so thought to be counterfeit, fake. In fact, this is an extremely one-sided and erroneous identification method. The fact that stainless steel will "rust", also magnetic. 
Stainless steel is more than 60% of the iron matrix, join the network, high alloy nickel, molybdenum and other alloying elements, its biggest feature is the corrosion resistance is strong, but not absolute, stainless steel does not rust. In some coastal areas or areas with serious air pollution, while larger chloride ion content in the air, exposed to the atmosphere of the stainless steel surface may be some rust, but these only surface rust, will not erode the steel inside the base. 
Many types of stainless steel, most with a magnetic, so identification of stainless steel with a magnet adsorption is not a scientific method. 
Usually used as a decorative tube plate austenitic stainless steel type 304 most material, in general, is a non-magnetic or weakly magnetic, but the chemical composition fluctuations caused by smelting or processing may also occur in different magnetic states, but it can not be considered counterfeit or substandard, which is what causes it? 
Mentioned above austenite is non-magnetic or weakly magnetic, and martensite or ferrite is magnetic, due to improper segregation smelting or heat will cause a small amount of austenitic 304 stainless steel martensite or ferrite body tissue. In this way, 304 stainless steel with a weak magnetic. 
In addition, 304 stainless steel after cold working, the organizational structure will be transformed to martensite, the greater the degree of cold deformation martensite transformation, the more the greater the magnetic steel. Like steel batch number, production Φ76 pipe, no significant magnetic induction; production Φ9.5 tube, Ling bending deformation due to significantly larger number of magnetic induction; produce rectangular tube tube due to deformation than large, especially knuckle part , more intense magnetic distortion is more obvious. 
To completely eliminate the magnetic steel above 304 causes, can be opened to restore stability austenite at high temperature solution treatment, thereby eliminating magnetic. 
In particular, proposed that the magnetic 304 stainless steel caused by the above reasons, and other materials of stainless steel, such as 430, magnetic steel is absolutely not the same level, that always shows the magnetic steel 304 is weakly magnetic. 
Where stainless steel parts, such as electroless plating or other coating requirements, are generally required in pretreatment (including pickling go black, polished, etc.) through the passivation treatment to use when finished or assembled parts. Suzhou Xiang Xing Stainless Steel Ltd. was established in 1999, is a professional sales and processing of stainless steel-based enterprises. The company sells a variety of models of stainless steel pipes and stainless steel sheet, such as: stainless steel folding scissors Suzhou, Suzhou, stainless steel pipe, stainless steel covers Suzhou, Suzhou stainless steel production, the company has many sets of CNC bending machine slot machine stainless steel shears, plasma cutting machine laser machine and other advanced equipment and excellent production and installation team to undertake the processing and production of stainless steel decorative works. Passivation of stainless steel to improve the stability of the thermodynamic medium in the environment, the prevention of localized corrosion of the stainless steel, the stainless steel surface has a sufficient cleanliness and can also eliminate the hot workability of stainless steel oxide surface. 
Passivation of stainless steel can be divided into two types of wet and dry. Concrete can be divided into many types. 
Passivation of stainless steel depends both on the passivation process, also depends on the stainless steel itself, there are specific factors contained elements of stainless steel, stainless steel, metallurgical structure, stainless steel processing status. The composition elements, chromium, nickel are strongly passivating elements, followed by passivation of iron, and therefore, chromium, the higher the nickel content, the greater the passivation of stainless steel. Austenitic, ferritic stainless steel has more uniform organization can passivation better, martensitic stainless steel heat-treated to strengthen its multi-phase microstructure of the organization, which is not strong passivation. The passivating stainless steel surface after machining is preferably smooth, casting, sand blasting, etc. The resulting surface roughness is not conducive to passive.
Note: without our permission, any organization or individual shall not possess Zhangjiagang City in Jiangsu Machinery Co., Ltd. on behalf of advertising and, if found, the company will pursue its legal responsibility and demanded financial compensation!
All rights reserved:Zhangjiagang Liye Machinery Co.,Ltd Mob:86-13812981723 Contact:Miss Sarah
Fax:+86-512-58968681 Add:No.174th Zhenbei Road Leyu Town, Zhangjiagang City E-mail:liye@liyemachine.com