What is heat treatment stress

What is heat treatment stress

The residual force of heat treatment is the stress of the workpiece after heat treatment, and the shape of the workpiece. Size and performance are extremely important. When it exceeds the yield strength of the material; It causes the distortion of the workpiece, which can cause the workpiece to crack when it exceeds the limit of the strength of the material. This is its harmful side and should be reduced and eliminated.
But under certain conditions, the control of stress can improve the mechanical properties and service life of the parts, which can be beneficial. The distribution and change of stress during heat treatment are analyzed, and the reasonable distribution of steel is of great practical significance to improve the product quality.

How do you select the oil surface pressure

How do you select the oil surface pressure

In the use of a vacuum quenching furnace oil quenching heat treatment process, under low vacuum pressure and vacuum cooling capacity of quenching oil drops, for some steel, may reach the purpose of quenching. Therefore, before using the vacuum quenching furnace to quench indoor filling the high purity of neutral or inert gas, in order to create constant pressure on the oil, so that you can fully steel quenching and get the surface of the light. The critical quenching pressure is the lowest level of liquid pressure at the same time as the same hardening hardness under atmospheric pressure. The characteristics of critical quenching pressure and vacuum quenching oil are related to the hardening of steel.
When hardening of hardened steel by vacuum quenching furnace, it is necessary to inflate and then harden into oil. The pressure in the oil is higher than the critical quenching pressure. In general, you can adjust to about 5 times 104Pa, but not below 1.0 x104pa. For some medium hardened steel, it also requires the use of the first gas and then the oil in the process of quenching. The pressure of the oil can be adjusted to about 1.0 times 104Pa, but not for less than 5 times 103Pa. For some good quenching hardness steel can choose air or air in this way, if with the method of gas, then choose inside. In order to prevent and reduce the pollution of the steam entering and vacuum quenching furnace heating chamber can choose to use higher air pressure, the gas should be adopted by the high purity of the inert or neutral gas. If you use a post-inflation method, you can choose a gas that is low in purity, and the pressure can be lower. If the method is not inflated, then the workpiece does not need to be inert or neutral until the oil is in the oil.

The purpose and structural characteristics of vacuum high-pressure air quenching furnace

The purpose and structural characteristics of vacuum high-pressure air quenching furnace

   vacuum high-pressure gas quenching furnace is mainly used for the quenching of high speed steel, industrial mold steel and stainless steel. Solid solution of stainless steel and titanium alloy; The vacuum heat treatment of magnetic material and high temperature brazing and vacuum sintering, and the convection blower can also carry out low temperature tempering.
Structure features: heating chamber adopts stainless steel skeleton, new carbon felt composite material, less deformation, resistance to high temperature and high pressure air scour, long service life, easy maintenance, using graphite tube heater, easy installation and maintenance, low failure rate. Air cooled by jet cooling way, graphite nozzle circumference uniformly distributed, make a high pressure air flow is more reasonable, part of the main duct air volume size adjustable, customers can according to the characteristics of the artifacts the size of the control part of the main duct airflow, can effectively control the workpiece deformation. High speed high-pressure high flow fan, copper and copper high efficiency round heat exchanger, achieve high speed cooling. The fan can adopt single speed, two-speed, variable frequency speed regulation various ways, control the wind and cold speed. The whole metal structure can be used in the heating room to meet the requirement for the solid solution of titanium alloy and precision alloy. The electric control system adopts PLC and programmable temperature controller, and realizes the automatic, semi-automatic and manual control mode, and the operation is flexible.

Characteristics and selection of vacuum tempering furnace

Characteristics and selection of vacuum tempering furnace

Vacuum tempering furnace is suitable for high speed steel, die steel, tool steel, alloy steel, titanium alloy etc. Soft magnetic material, silicon steel sheet, electrician pure iron, copper alloy and other materials bright annealing. Remove the forging parts, welding parts, cold stamping parts, and the residual internal stresses of the workpiece to prevent deformation and cracking of the workpiece.
Vacuum furnace characteristics:
The operation is convenient, manual/automatic free switch, can achieve full automatic control, fully avoid the human error in the working procedure.
Have perfect alarm system, can provide protection to the equipment effectively.
According to the characteristics of low temperature and large furnace quantity for some vacuum furnace process, the application of convection heating should be considered. To meet the demand of heating speed and temperature effect in the heat return process.
4, for some tubular, slender, thin wall parts annealing treatment, suggest that choose vertical jacket material or bottom loading structure, can effectively solve the problem of deformation.
Vacuum furnace selection reference: the user can choose the tempering temperature according to the workpiece, choose the nickel-chrome heater or the molybdenum heater. Molybdenum nickel chrome heater is the highest temperature is 700 ℃, the heater the highest temperature is 1100 ℃. The corresponding heating power is different.