The workpiece is heat treated using a medium frequency induction heating machine to produce oxide scale defects. How much do you know about its hazards?

When the workpiece is heat treated with a medium frequency induction heating machine, affected by the heating temperature, heating speed and surrounding environment, the contact between the workpiece and the air may produce oxide scale. When it comes to scale, some people may not care and think it is irrelevant. Today, the editor will tell you about the dangers of oxidized skin.

(1) Causes a large loss of metal materials: The oxide scale produced when the metal is heated by a medium-frequency induction heating machine will cause a large loss of metal materials. Under normal circumstances, 0.5%-3.0% of the metal is burned every time the steel billet is heated. In severe cases, the burn loss rate can even reach 5%.

(2) Affects the surface quality of the forging: If the oxide scale on the blank is not cleaned during die forging, once the forging is pressed into the forging, the surface of the forging will be pitted, and in severe cases it will become a scrap. There is oxide scale on the surface of forgings, which will lead to uneven structure and properties (such as uneven hardness) during heat treatment.

(3) The oxide scale (alkaline) peels off on the furnace bottom and reacts chemically with the furnace bottom refractory material (acidic) to cause the furnace bottom to reflow, thereby shortening the service life of the heating furnace.

(4) Add the process of removing oxide scale: not only the process of removing oxide scale must be included in the production process of forgings, but also the process of shot blasting, sandblasting or pickling of forgings.

(5) Reduce the service life of the mold: Due to the high hardness of the oxide scale, the oxide scale in the mold cavity will accelerate the wear of the mold cavity, thereby reducing the service life of the mold and also affecting the life of the machining tools.

After reading the above description, I believe everyone has a certain understanding of the hazards of oxide scale. Therefore, reducing and preventing metal oxidation is of great significance, which can not only improve the quality of forgings and the service life of molds, but also reduce the cost of forgings. For workpiece heat treatment, reducing the oxidation phenomenon of the workpiece also helps to improve the heat treatment quality of the workpiece.