Press quenching is to place the workpiece to be quenched on a special quenching press die, and while applying external force, the press sprays quenching oil (the press has an oil cover to cover the workpiece and the die) to quench the workpiece, The die of the press machine is divided into an upper die and a lower die. The lower die is generally a flat surface with grooves, and the upper die is a die that matches the shape of the workpiece. Sometimes, the pressure-quenching die steel is suddenly deformed during heat treatment, so what is going on? The common deformation of pressure-quenching die steel during heat treatment
The reasons are as follows:
1. Its own stress state:
The heat treatment deformation of press quenching die steel has an important influence on the stress state of the workpiece itself before quenching. Especially for some complex shapes and large feeds
If the residual stress of the workpiece processed by mass machining is not eliminated, it will have a great influence on the quenching deformation.
2. The original arrangement before quenching:
The heat treatment deformation of press-quenched die steel generally has a great influence. For example, if spherical pearlite is larger than flaky pearlite in volume and high in strength, the quenching deformation of the pre-spheroidized die steel workpiece is relatively small. Especially for some high carbon alloy tool steels, the spheroidization grade has a great influence on the correction of heat treatment deformation cracking and quenching deformation, so we can generally use the spheroidization arrangement of 2.5 to 5 grades.
3. Strip carbide distribution:
Because the workpiece expands parallel to the carbide strip after quenching, the direction perpendicular to the carbide strip is shortened, and the larger the carbide particles, the larger the strip.
The direction of the expansion is greater. For ledeburite steels such as Cr12 type steel and high-speed steel, the influence of the shape and distribution of carbides on the quenching deformation is particularly obvious. thus
On heating, the less swollen carbides inhibit the elongation of the matrix in the direction of the carbides dispersed in the strips, while on cooling, the lesser shortening carbides hinder the shortening of the matrix. Therefore, the dispersion of strip carbides will also have a certain influence on the heat treatment deformation of press hardening die steel.
The common causes of heat treatment deformation of press quenching die steel are briefly introduced here. I don’t know if you have a complete grasp of the above questions? If you still have doubts and want to know more, you can leave us a message, Aojie Mould will provide you with warm service, and look forward to your reading and feedback.
Post time: Jan-14-2022