1) Stainless steel Resistance to air, steam, water and […]
1) Stainless steel
Resistance to air, steam, water and other weak corrosive media and acid, alkali, salt and other chemical etching medium corrosive steel. Also known as stainless steel. In practical applications, steels that are resistant to weak corrosive media are often referred to as stainless steels, and steels that are resistant to chemical corrosion are known as acid-resistant steels. Because of the difference in chemical composition between the two, the former is not necessarily resistant to chemical media corrosion, while the latter is generally non-rust. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel. Chromium is the basic element that gives corrosion resistance to stainless steel. When the chromium content in the steel reaches about 12%, chromium reacts with oxygen in the corrosive medium to form a thin oxide film on the surface of the steel (self-passivation film). , can prevent further corrosion of the steel substrate. In addition to chromium, the commonly used alloying elements are nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the various requirements of the stainless steel structure and performance requirements. Stainless steel is usually divided into matrix structure: 1 ferritic stainless steel. Chromium 12% to 30%. Its corrosion resistance, toughness and weldability increase with the increase of chromium content, and its resistance to chloride stress corrosion is superior to other types of stainless steel. 2 Austenitic stainless steel. Chromium is more than 18%, also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. Good overall performance, resistant to many media corrosion. 3 Austenite - Ferritic duplex stainless steel. It combines the advantages of austenitic and ferritic stainless steels and has superplasticity. 4 martensitic stainless steel. High strength but poor plasticity and weldability. Usually civilian stainless steel has the following number: 304,303,302
, 202, 203, 201, etc. In outdoor furniture, the 304 model is used more, so the hardness of stainless steel model, corrosion resistance is strong, so stainless steel exposed products often use this model. For the products with low requirements for corrosion resistance, or products that are sprayed on the surface of stainless steel, 201 or 202 stainless steels are generally used. This type of stainless steel has no stronger corrosion resistance than 304. Usually, these different types of stainless steel are difficult to distinguish in appearance. Under normal circumstances, we will use stainless steel detection fluid to distinguish. Due to the antiseptic properties of stainless steel, the cost-effectiveness in furniture materials is also high. Stainless steel in the production process is divided into polishing and drawing points. Polished stainless steel is very reflective, but it is easy to mix with ferroelectricity, so it is not used on outdoor furniture, used for tableware, etc.; brushed stainless
The steel treatment has a flexible metallic color, and the appearance gives a feeling of high grade, which is a common method for outdoor furniture .
Aluminum materials are widely used in outdoor furniture production due to their excellent corrosion resistance, lighter weight, higher ductility, and moderate strength. Usually this material will be sprayed on the surface during production to match the color. Or the surface is electrochemically treated.
The advantage of iron materials is their strength. They are used in products with good support. The disadvantages are heavy weight, inconvenience to handling, corrosion, and rust. Therefore, in the production of furniture, it is mostly used for low-end cast iron products. In normal use, it needs to be treated with rust prevention. Such as common park chairs and so on.
4) Stainless iron
The so-called “stainless iron” means scrap iron, lead, steel, etc. that have been recycled through the secondary reheating process and are processed by removing “magnetic”. The stainless iron is chromium and nickel-free. It is also
Cr stainless steel, there is a certain degree of corrosion resistance! Stainless iron is not a common saying, but it is generally believed to have ferromagnetic stainless steel.