How do I identify stainless steel and rust-free iron? What’s the difference?
The metal market is quite large, good or bad. Many illegal enterprises exchange rust-free iron for stainless steel for profit. Many people also often can’t tell which is the real thing. So how do you identify this situation?
Let’s take a look first. What is stainless steel and rust-free iron?
1. Stainless steel
Stainless steel, as the name suggests, is not easy to rust steel. It is important to note here that it is not easy to rust, nor is it impossible to rust. Objectively speaking, however, stainless steel is not prone to rust or corrosion. The stainless steel surface has a protective film, i.e. a chromium-rich oxide film. Due to the presence of this film, stainless steel has a properties that are not prone to rust and corrosion. Study surface: With the increase of chromium content in steel, corrosion resistance of steel in weak media such as atmosphere, water and oxidizing medium such as nitric acid increases. When the chromium content reaches a certain percentage, the corrosion resistance of steel changes dramatically, from easy to rust, from corrosion to corrosion resistance.
2. Before rust-free iron, there was no such term as rust-free iron. The name was born after Focus Interviews came to light, when it accounted for 65 per cent of the market, while the real 304 stainless steel products were not available because of high prices. Rust-free iron is made from scrap iron, lead and steel recovered through a secondary furnace and subsequently de-“nourished”. Generally speaking, the naked eye can not distinguish, magnets can not distinguish. As a result, many illegal enterprises produce and use them on the market and use them in many engineering projects and decorative sites.
How do we tell if stainless steel is true or false?
In fact, the easiest way is price! The most important reason for the high market share of stainless steel is its low price. According to the current stainless steel market, the price of stainless steel in 10000-20000 yuan, and stainless steel price is only 5000-7000 yuan, which is very different. In addition, in terms of tensile strength, stainless steel tensile strength of 160-180 MPa, while the national standard stainless steel tensile strength of 530-620 MPa, the difference is obvious. Such low tensile strength is prone to accidents. Therefore, in the case of low-cost stainless steel, you should carefully consider. Don’t fall into a deep pit and don’t know, now the price of stainless steel is transparent, rust-free iron rarely come out to make waves. However, we must still firmly prohibit rust-free iron products.
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