Publish Time: 2022-07-14 Origin: Site
To accurately identify 304 stainless steel materials, we must do the composition analysis of metal materials. It involves internal sampling of metal materials, sample melting, chemical analysis of the content of various metal elements in steel, and finally judge whether it is really 304 stainless steel through the national standard.
304 stainless steel is a common material in stainless steel, with a density of 7.93g/cm ⊃3;； It is also called 18/8 stainless steel in the industry, which means it contains more than 18% chromium and more than 8% nickel; High temperature resistance 800 ℃, with good processing performance and high toughness, it is widely used in industry, furniture decoration industry and food and medical industry. However, it should be noted that the content index of food grade 304 stainless steel is more strict than that of ordinary 304 stainless steel.
304 is a kind of universal stainless steel, which is widely used to make equipment and parts requiring good comprehensive performance (corrosion resistance and formability). In order to maintain the inherent corrosion resistance of stainless steel, the steel must contain more than 18% chromium and more than 8% nickel. 304 stainless steel is a brand of stainless steel produced according to American ASTM standards.
For 304 stainless steel, the Ni element in its composition is very important, which directly determines the corrosion resistance and value of 304 stainless steel.
Identify the common major misunderstandings of 304 stainless steel!
① Judging by the surface gloss and smoothness of steel - serious error, judging by the surface texture of steel basically has no accuracy. 1. The surface may be worn; 2. Different manufacturing processes will also lead to different surface texture; 3. More unscrupulous businesses are plating 304 stainless steel film on the surface of steel. In fact, there are other cheap varieties of steel inside
② 304 steel inspection potion - seriously inaccurate. 1. The color difference of liquid medicine is large; 2. The potion can only roughly identify the content of a certain chemical element, such as nickel and manganese; However, according to the national standard, 304 stainless steel must meet the standard of 7 elements to be considered as 304 stainless steel (elements are: carbon, sulfur, phosphorus, silicon, manganese, nickel, chromium); 3. The formula and concentration of the potion are uneven
③ Judging 304 stainless steel through magnets is a misunderstanding. 304 stainless steel is judged by the elements: carbon, sulfur, phosphorus, silicon, manganese, nickel and chromium. There is no iron element in it, and the strength of magnetism cannot determine whether it is 304 stainless steel.