How to eliminate oxidation on the surface of ASTM A242 Type1 weather resistant steel plate

If ASTM A242 Type1 weather resistant steel plate is heated to a certain high temperature in the air during welding or grinding, chrome oxide heat return color will appear on both sides of the weld, the lower surface and the bottom of the weld.

The heat return flame is thinner than the oxidation protective film, and it is obvious.
The color is determined by ASTM A242 Type1 weather resistant steel plate thickness and can appear in rainbow colors, blue, purple to pale yellow and brown. Thicker oxides are generally black. It is due to ASTM A242 Type1 weather resistant steel plate staying at high temperatures or at higher heights for long periods of time.

When any of these oxide layers are present, the chromium content on the surface of ASTM A242 Type1 weather resistant steel plate is reduced, resulting in reduced corrosion resistance in these areas.
In this case, not only should the heat return flame and other oxide layers be eliminated, but also the metal layer of ASTM A242 Type1 weather resistant steel plate should be cleaned.