Stainless steel wire is widely used in our daily life, such as ball point pen springs, cart baskets, chains on popular women's bags, protective covers for electric fans, return wires for umbrellas, coat hangers, barbecue racks, barbecue forks, and so on. All are made of stainless steel wire with different standards. Here, we will explain the differences in the material of stainless steel wire, so that you can better choose and purchase stainless steel wire suitable for you.

1. Magnetic experiment method

The magnetic experiment method is a relatively common and simple method to distinguish between austenitic stainless steel and ferritic stainless steel. Austenitic stainless steel is a diametrically opposed magnetic steel, but after cold working under high pressure, it will have a slight magnetism; The plain chromium steel and low alloy steel are both strong magnetic steels.

2. Nitric acid point test

A prominent feature of stainless steel wire is its inherent corrosion resistance to concentrated and dilute nitric acid, which makes it easy to distinguish it from most other metals or alloys. However, high carbon type 420 and 440 steels are slightly corroded during the nitric acid spot test, and nonferrous metals are immediately corroded when they encounter concentrated nitric acid, while dilute nitric acid has a strong corrosive effect on carbon steel.

3. Copper sulfate spot test method

The copper sulfate spot test is a simple way to quickly distinguish between ordinary carbon steel and all types of stainless steel wires. The concentration of the copper sulfate solution used is between 5% and 10%. Before conducting the spot test, the experimental area should be thoroughly cleaned of oil or other impurities, and a small area should be polished with a grinder or soft abrasive cloth. Then, the test solution should be dropped onto the polishing area. Generally, carbon steel or iron will form a layer of metal copper on the surface within a few seconds, The surface of stainless steel subjected to spot testing does not exhibit copper deposition or copper color.

4. Sulfuric acid experimental method

Sulfuric acid immersion in stainless steel can distinguish 302 and 304 from 316 and 317. The cut edge of the sample needs to be finely ground, and then cleaned and passivated in sulfuric acid with a volume concentration of 20% to 30% and a temperature of 60 to 66 ℃ for half an hour. The volume concentration of the sulfuric acid solution is 10%. When heated to 71 ℃, 302 and 304 are immersed in the solution, the steel is rapidly corroded and many bubbles occur, and the sample turns black within a few minutes; The samples of 316 and 317 steel are not subject to corrosion or corrosion is slow (no bubbles occur), and do not discolor within 10-15 minutes of testing. If a sample with known composition is selected for approximate comparison, the experiment can be made even more complex