Application of vacuum heat treatment technology

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Vacuum hardening

The main purpose of vacuum hardening is to improve and strengthen the quality of metal components, especially the quality of the surface layer. For tool steel, vacuum hardening can ensure sufficient hardness requirements, and the surface brightness is good, deformation is small, hardness is high and uniform, service life is long, post-processing technology is simple, and production cycle is short.

After vacuum hardening, the surface of steel is bright because there is no oxide film on the supply surface, and the oil impurities attached to the supply surface are volatilized, making the surface of metal parts shiny. Vacuum hardening is slow and uniform. After air-cooled quenching, the workpiece does not need to be moved for cooling in situ, so the deformation is small and regular. There is no oxidation and decarburization after vacuum quenching. Due to the high quenching heating temperature of high-alloy tool steel, the highly active surface after vacuum heating will be instantly carburized during oil quenching, forming a small layer of carburized layer, so the hardness after vacuum quenching is higher and more uniform than that during ordinary quenching, and there will be no quenching soft spots. The degassing effect during vacuum heating can improve the strength, wear resistance, anti-seizure performance and fatigue strength of the material, so the life of the workpiece after vacuum quenching is generally higher. It is reported that the average life of the mold can be increased by more than 30% after vacuum hardening, and some can be increased to 4 times.

Vacuum Hardening Furnace

Model	Working Zone Size (W*H*L)	MAX Temperature	Cooling Gas Pressure	Ultimate Pressure	Temperature Uniformity	Loading Capacity
RVGQ-446	400*400*600mm	1350℃	6/10/15/20Bar	6.7*10-4Pa/6.7*10-1Pa	±5℃	200Kg
RVGQ-557	500*500*700mm	1350℃	6/10/15/20Bar	6.7*10-4Pa/6.7*10-1Pa	±5℃	300Kg
RVGQ-669	600*600*900mm	1350℃	6/10/15/20Bar	6.7*10-4Pa/6.7*10-1Pa	±5℃	500Kg
RVGQ-7710	700*700*1000mm	1350℃	6/10/15/20Bar	6.7*10-4Pa/6.7*10-1Pa	±5℃	700Kg
RVGQ-8812	800*800*1200mm	1350℃	6/10/15/20Bar	6.7*10-4Pa/6.7*10-1Pa	±5℃	1000Kg
RVGQ-9915	900*900*1500mm	1350℃	6/10/15/20Bar	6.7*10-4Pa/6.7*10-1Pa	±5℃	1200Kg
Remark: The working zone of equipment could be customized base on customer’s production.

Vacuum gas quenching

Vacuum gas quenching is a process in which the workpiece to be processed is heated in a vacuum state, and then rapidly cooled in a high-pressure, high-flow cooling gas to improve the surface hardness of the workpiece to be processed.

Compared with ordinary gas quenching, oil quenching, and salt bath quenching, vacuum gas quenching has obvious advantages: ① The surface quality of the workpiece is good, no oxidation, and no carbon increase; ② Good quenching uniformity and small workpiece deformation; ③ Good quenching strength controllability and controllable cooling rate; ④ High productivity, eliminating the cleaning work after quenching; ⑤ No environmental pollution.

Vacuum tempering

The purpose of vacuum tempering is to maintain the advantages of vacuum quenching (products are not oxidized, decarburized, smooth surface, no corrosion pollution, etc.). If vacuum tempering is not used, the superiority of vacuum quenching will be lost. This is especially true for precision tools that are not finished after heat treatment and require multiple high-temperature tempering.

The application of vacuum tempering is closely linked to vacuum quenching. All mechanical parts after vacuum quenching must undergo vacuum tempering in order to reduce or eliminate quenching stress, ensure corresponding organizational transformation, improve the plasticity and toughness of the material, obtain hardness and strength, stabilize the size of the workpiece and other process requirements.

Learn More:

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