Vacuum oil quenching heat treatment

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Vacuum quenching oil (requirements for quenching oil):

(1) Low vapor pressure, not easy to volatilize;

(2) There are few impurities and carbon residues, and the acid value is low;

(3) Low critical pressure and good cooling performance;

(4) good thermal stability;

Characteristics of quenching oil

Comparing the hardness with ordinary quenching oil and mineral oil under vacuum quenching heating, it is concluded that:

(1) The hardness of ordinary quenching oil after quenching under normal pressure (0.1MPa) is 66HRC, and the sample can be completely quenched. However, as the pressure decreases during quenching, the hardness decreases sharply, and it drops to the lowest when it is below 5×104Pa. The workpiece cannot be hardened;

(2) Mineral oil is quenched under normal pressure, only the hardness of the sample reaches 42HRC, the hardness increases after the pressure drops, and the quenching hardness tends to decrease under lower pressure

(3) The vacuum quenching oil can be quenched to a high hardness above 63HRC in a wide area, which creates conditions for the high hardness of tool steel vacuum oil quenching.

The amount of vacuum quenching oil: the amount of quenching oil should be large enough. Generally, the ratio of workpiece weight to oil weight is 1: 10 to 1: 15.

Vacuum degree: a certain content of water will bring adverse consequences; when the hydraulic pressure is reduced, the oil will boil, which will seriously destroy the vacuum; the vacuum of the furnace should be maintained every time the furnace is stopped.

The use temperature of quenching oil: 40 ~ 80 ℃ is suitable, too low, the hardness is uneven; too high, it is easy to cause pollution and accelerate the aging of the oil.

Stirring device: strengthen the circulation and convection of the oil, if it is insufficient, there will be soft spots and soft bands; if it is too strong, it will cause large deformation.

Vacuum oil quenching is suitable for alloy tool steel, high-carbon high-chromium alloy steel, high-speed tool steel and other mold steels. It adopts special vacuum oil quenching. Vacuum oil quenching is especially suitable for molds that require high strength and toughness.

Equipment selection: The VOGQ-2 series vacuum oil quenching furnace produced by SIMUWU is a high-quality product for the vacuum oil quenching process of tooling and molds. The good temperature control accuracy and temperature control uniformity ensure the effective progress of the vacuum oil quenching process. SIMUWU specializes in the manufacture of vacuum furnaces, has more than ten years of relevant experience, and has a good reputation in the field of vacuum furnace manufacturing. The product line includes vacuum annealing furnace, vacuum air quenching furnace, vacuum brazing furnace, etc., which are widely sold in developed and developing countries.