Flame quenching is a quenching method that uses acetylene-oxygen flame (the highest temperature is 3 100℃) or gas-oxygen flame (the highest temperature is 2000℃) to heat the surface of workpiece at high speed, and then spray water to cool it. Acetylene-oxygen flame surface quenching is commonly used, which has the advantages that other heat treatments do not have:

(1) is not easy to produce surface oxidation and decarbonization.

(2) It is not limited by site environment and workpiece size, and has wide applicability and simple operation.

(3) Simple equipment, less investment and low cost.

(4) Suitable for single piece or small batch production, and also suitable for local quenching requirements of large workpieces, such as large gears, rollers, large housings (motor housings) and guide rails.

There are many advantages, but there are also some disadvantages.

(1) quality is difficult to control stably.

(2) Most of them are operated manually, observed by naked eyes, and master the temperature. The surface is easy to melt, overheat and crack, so it is difficult to achieve uniform quenching layer and high surface hardness.

(3) It is difficult to realize mechanized flow production.