Heat treatment protection coating knowledge

The heat treatment protective coating is used to protect the workpiece and prevent oxidation or decarburization when the workpiece is heated.
The general technical requirements of heat treatment protective coatings are stipulated in the JB/T5072-1991 standard: heat treatment protective coatings have the ability to resist alloying element depletion and interference for stainless steel, high-temperature alloys and titanium alloys; and have certain protection against structural steel and tool steel. Decarbonization capacity. The protective coating should be able to satisfy the total decarburization depth of less than or equal to 0.075mm, viscosity of 25~65s, raw material fineness no more than 45Um, no agglomeration, and good wettability for spraying and brushing. The coating should be uniform and complete, no tumor marks, and good adhesion. It should be dried within 2 hours at room temperature or within 30 minutes within the temperature range of 60 to 100 degrees. The coating should have good peeling performance. After quenching and water cooling, more than 90% of the coating area should be able to fall off by itself; after oil cooling, more than 80% of the coating should be able to fall off by itself, and the residual coating should be easy to remove. The layer should not contaminate the quenching medium. In addition, the coating composition must not contain elements that damage or contaminate metal parts, and no harmful gases or substances should be emitted during the heating process.