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What are the ways to identify the material of stainless steel wire
- 2019-10-30-

  Stainless steel wireAll over our livesAmong them, the ballpoint pen springs, cart carrying baskets, chains on popular ladies' bags, protective covers for electric fans, pull-back cords for umbrellas, hangers, barbecue racks, barbecue forks, etc., are all of different standards. It is made of stainless steel wire, so here we will explain to you what are the differences in the material of stainless steel wire, so that you can better choose the stainless steel wire that suits you.

1. Magnetic experiment method

The magnetic experiment method is a more common simple way to distinguish austenitic stainless steel from ferritic stainless steel. Austenitic stainless steel is a non-magnetic steel, but it will have mild magnetic properties after cold working under high pressure; while the simple chromium steel and Low alloy steels are all strong magnetic steels.

2. Nitric acid spot test method

A distinctive feature of stainless steel wire is its inherent corrosion resistance to concentrated nitric acid and dilute nitric acid. This performance makes it easy to distinguish it from most other metals or alloys. However, high-carbon 420 and 440 steels are slightly corroded during the nitric acid spot test. Non-ferrous metals are corroded immediately when they encounter concentrated nitric acid, while dilute nitric acid is fiercely corrosive to 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 5%-10%. Before the spot test, the experimental area should be thoroughly cleaned of oil or For other impurities, use a grinder or soft abrasive cloth to polish a small area, and then drop the test liquid to the polished place. Ordinary carbon steel or iron will form a layer of surface metal copper in a few seconds, and try the appearance of stainless steel. Then there will be no copper precipitation or the appearance of copper color.

4. Sulfuric acid experiment method

Sulfuric acid immersion stainless steel can distinguish 302 and 304 from 316 and 317. The cut edge of the sample must be finely ground, and then cleaned and passivated in sulfuric acid with a volume concentration of 20%-30% and a temperature of 60-66°C for half an hour. The volume concentration of the sulfuric acid solution is 10% and heated to 71°C. When 302 and 304 are immersed in the solution, the steel is quickly corroded and many bubbles occur, and the sample turns black within a few minutes; while the 316 and 317 steel samples are not corroded or corroded very slowly (no bubbles). The experiment does not change color within 10-15 minutes.