1. Nitric acid point test:
A major feature of square pipe is its inherent corrosion resistance to dilute and concentrated nitric acid.
2. Magnetic test:
The square tube magnetic test is the simplest method to distinguish the annealing form. It becomes slightly magnetic after being cold worked under high pressure; while pure low alloy steel and chromium steel are both highly magnetic steels.
3. Sulfuric acid test:
The volume concentration of the sulfuric acid test solution is 10% and it is heated to 71°C. When the square tube is immersed in this hot solution, it is rapidly corroded and a large number of bubbles are generated, and the sample quickly turns black in a few minutes.
4. Copper sulfate point test:
The copper sulfate point test is the easiest and fastest way to distinguish ordinary carbon steel from all types.
