1. Magnetic test method
The magnetic testing method is the most primitive of the easiest way to distinguish the most common iron austenitic stainless steel and ferritic stainless steel, austenitic stainless steel is non-magnetic steel, but the big pressure of cold processing will have mild magnetic; pure chrome steel and low alloy steel is strong magnetic steel.
2, nitric acid point test
A notable feature of stainless steel wire ropes is their inherent corrosion resistance to concentrated nitric acid and dilute nitric acid, which makes it easy to distinguish between most other metals or alloys.
But the high carbon type 420 and 440 steel are slightly corroded when they are subjected to nitric acid point test, and the nonferrous metals are corroded immediately when they are concentrated nitric acid, while the dilute nitric acid is strongly corrosive to carbon steel.
3. Copper sulfate spot test
Copper sulfate test is the most convenient way to quickly distinguish between ordinary carbon steel and all kinds of stainless steel wire rope, the use of copper sulfate solution concentration is 5%-10%, the point before the test, the test area should completely remove oily or other impurities, a small area and polished by grinding machine or soft cloth, and then the solution to drop grinding, ordinary carbon steel or iron will be within a few seconds the metal surface to form a layer of copper, and stainless steel test surface does not produce precipitation of copper or copper color.
4 sulfuric acid test method
Immersion stainless steel can distinguish between 302 and 304 and 316 and 317. The sample cutting edge after fine grinding, and then 20%~30% in volume concentration, temperature of 60~66 degrees of sulfuric acid cleaning and passivation in half an hour, the volume concentration of sulfuric acid solution was 10%, heated to 71 DEG C, 302 and 304 in solution, the steel is rapid corrosion and produce a lot of bubbles, black in a sample in 316 and 317; and the specimen of steel is not affected by corrosion or corrosion is very slow (no air bubbles), test color in 10~15 minutes. The tests can be made more accurate by using simultaneous tests of specimens with known components for approximate comparisons.