First, the magnetic test method, the magnetic test method is the most primitive and most common method.
Second, nitric acid spot test method, there are written high-speed steel plate will have inherent corrosion resistance to concentrated nitric acid and dilute nitric acid, this performance makes it can be easily distinguished from most other metals or alloys;.
Third, copper sulfate spot test method, copper sulfate spot test is a quick way to distinguish high-speed steel plate, it should be noted that the concentration of copper sulfate solution used is 5%-10%, before conducting the spot test, the test area should be thoroughly cleared of oil or other impurities, and polished with a grinding machine or soft abrasive cloth to polish a small area, and then the test solution drops to the grinding, ordinary carbon steel or iron in a few seconds will form a layer of surface metallic copper.
Fourth, the sulfuric acid test method, sulfuric acid submerged high-speed steel plate, the cut edge of the specimen to be finely ground, and then in the volume concentration of 20% to 30%, the temperature of 60 ~ 66 in the sulfuric acid cleaning and passivation for half an hour, the volume concentration of sulfuric acid solution is 10%, heated to 71, you can see the difference, the steel is rapidly corroded and produce a large number of bubbles, some will turn black in a few minutes, some are not corroded Or slow corrosion does not produce bubbles, the test in 10 to 15 minutes without discoloration. The test can be made more accurate if specimens with known composition are tested simultaneously for approximate comparison.
Post time: Mar-14-2022