How to identify 304 stainless steel？

304 stainless steel is a nationally recognized Food Grade Stainless Steel. It has good corrosion resistance and heat resistance and is used in the manufacture of high-end household items. The alloy content of 304 stainless steel is relatively high, so the price is much higher than ordinary steel, which often leads to unscrupulous merchants selling shoddy steel as 304 stainless steel products. Non-304 stainless steel products not only have poor rust resistance, but also direct contact with the human body, which will have adverse effects on health. In order to ensure the rights of everyone, here is a share of the knowledge about 304 stainless steel.

Method for distinguishing ordinary steel and 304 stainless steel

1. Use a magnet to identify. Ordinary steel has strong magnetic properties. 304 stainless steel is non-magnetic or weakly magnetic. When the same magnet is close to ordinary steel and 304 stainless steel, it can clearly feel the difference between the two.

2, the difference in color: after pickling stainless steel, the surface color is silver and white: chrome-nickel stainless steel color silver-white color; chrome stainless steel color white slightly gray gloss weak; chrome-manganese-nitrogen stainless steel color similar to chrome-nickel stainless steel slightly lighter. Surface color of stainless steel without pickling: chrome-nickel steel is brownish white; chrome steel is brownish black; chrome-manganese nitrogen is black (these three colors refer to the heavier oxidized color). Cold-rolled, unannealed chrome-nickel stainless steel with reflective white surface. In addition to Yuan Steel, stainless steel is generally pickled and white.

Distinguish between 201 and 304 stainless steel

1, 201 stainless steel grade: 1Cr17Mn6Ni5N. 304 stainless steel grade: 06Cr19Ni10 (or 0Cr18Ni9); due to the difference in chromium and nickel content and carbon content, 304 stainless steel tube is softer than 201 stainless steel tube, and 304 stainless steel is more corrosion resistant; 201 is mainly used for drying Area and quality requirements are not strictly decorative, 304 stainless steel can be used in bathrooms, kitchens and coastal wet areas.

2, friction spark identification method: you can point to the business of their lower corner materials, to cut, see sparks. Generally, the 202 stainless steel has a large amount of manganese, so the discounted spark is very boring, the fork is more, the 304 stainless steel spark is brighter, and the fork is less; if it is conditional, it can be sent to a professional quality inspection department for inspection.

3, special steel inspection syrup, this syrup can be purchased in the general hardware store, so you can not worry about the source of goods. 304 stainless steel, it is not discolored within 3-5 minutes after the inspection of the syrup, 201 stainless steel, the syrup will turn into dark brown red in an instant.