Research into the deformation status of precision and complex molds, as well as the causes of deformation, in order to investigate potential methods to reduce and control the deformation of precision and complex molds, with the end goal of improving the quality of mold products and their service lives. The choice of materials for the moldsIn order to manufacture more complex molds with widely different cross-sectional dimensions and to require less deformation after quenching, a mold company selected T10A steel as their material of choice due to the ease with which they could select their materials and treat them using heat. The required hardness range is between 56 and 60 HRC. The mold's hardness satisfies the technical requirements after it has been subjected to heat treatment; however, due to the mold's relatively significant degree of deformation, the mold is unable to be used and must instead be scrapped.
After some time, the company switched to using micro-deformation steel Cr12 steel for the manufacturing process. After heat treatment, the mold's hardness and its deformation were able to satisfy the requirements. Micro-deformation steel, such as air-quenched steel, should be utilized as frequently as possible during the manufacturing process of precise and complex molds that call for a lower degree of deformation. The effect of the material used in the moldA batch of Cr12MoV steel was shipped out by a factory to be used in the production of more intricate molds. The round holes in the die cast parts molds range from 60mm to 100mm. Because some of the mold holes had taken on an elliptical shape after being subjected to the heat treatment, the molds had to be discarded. In general, Cr12MoV steel is a slightly deformed steel, and there should not be any significant deformation at all.
After conducting metallographic analysis on molds that had been severely damaged, we discovered that the steel used to make the molds contains a significant amount of eutectic carbides, which are organized into bands and blocks. The presence of uneven carbides in the mold steel, which are distributed in a particular direction, is the root cause of the mold ellipse. When compared to the expansion coefficient of the steel matrix, the carbides have an expansion coefficient that is approximately thirty percent lower. When it is heated, it stops the expansion of the mold's die casting China inner hole, and when it is cooled, it does the opposite. It is important to prevent the inner hole of the mold from contracting, as this would result in an unevenly deformed inner hole, which would give the impression that the mold's round hole is actually elliptical.
When manufacturing molds that require a high level of precision and complexity, it is important to select mold steel that has a low carbide segregation and avoid selecting inexpensive steel that was produced by a small number of steel factories. For die steels that have severe segregation of carbides, reasonable forging should be carried out so that carbide crystal blocks can be broken, the level of uneven distribution of carbides can be reduced, and anisotropy in the properties can be eliminated. On the forged die steel, a heat treatment called quenching and tempering should be performed in order to obtain a fine and dispersed sorbite structure as well as uniform carbide distribution. This will help to reduce the amount of deformation that occurs in precision and complex dies after the heat treatment. In the case of molds that are of a larger size or cannot be forged, a treatment known as solid solution double refinement can be utilized to refine and evenly distribute carbides. Additionally, rounding the edges and corners of the mold can accomplish the goal of reducing the heat treatment deformation of the mold.
Preventative measures to be taken against the heat-treating-induced deformation of precision molds
Preventative measures to be taken against the heat-treating-induced deformation of precision molds.
Although we do not wish for the precision and complexity of the molds to be compromised in any way, this outcome is unavoidable. All that is left to do is get a handle on the deformation rules and investigate what caused them. Mold deformation can be minimized and better controlled by employing a variety of preventative measures. The use of micro-deformation mold steel with good material (such as air quenching steel) is recommended for molds that require a high level of precision and complexity. For mold steel that has severe carbide segregation, it is recommended that a heat treatment consisting of reasonable forging, quenching, and tempering be carried out. The solid solution double refining heat treatment is recommended for larger and more indestructible mold steels.
The design of the mold structure ought to be rational, the thickness ought not to vary an excessive amount, and the shape ought to be symmetrical. For molds that have a significant amount of deformation, the deformation law ought to be learned by heart, and machining allowance ought to be set aside. A combined structure can be utilized to create molds that are large, precise, and complex. Molds that are precise and complex should be pre-heated to get die casting manufacturer rid of any residual stress that was caused by the machining process. Control of the heating speed and temperature, as well as a reasonable selection of the temperatureSlow heating, preheating, and other methods of balanced heating can be used to reduce the amount of deformation that is caused by the mold heat treatment for precision and complex molds. If you want to guarantee that the mold will have a high level of hardness, you should try to use a process known as pre-cooling, graded cooling quenching, or warm quenching.
If the circumstances are suitable, vacuum heating and quenching, followed by cryogenic treatment after quenching, casting services should be utilized as much as possible for the production of precise and complex molds. The control of the mold's precision can be achieved through the use of pre-heat treatment, aging heat treatment, tempering and nitriding heat treatment, and aging heat treatment, respectively, for certain precision and complex molds. Cold welding machines and other repairing equipment with little thermal influence are used when repairing defects such as mold sand holes, pores, and wear. This is done to avoid the material deforming during the process of repair, which can be caused by thermal stress.
When choosing a machining center, it is important to take into account the dimensions of the mold in terms of both the size and the stroke of the table on the machining center. At the same time, both the method of clamping and the amount of space necessary for clamping ought to be taken into consideration. When working with large molds, it is important to take into account the substantial weight that will be placed on the workbench. The following types of objects are processed by various machining centers:1. Model cavities and insert slider molds are typically the types of molds that are processed by vertical mold machining centers. 2. Horizontal machining centers are typically utilized for the processing of large dynamic models. The cost of machining centers is high because horizontal machining centers have a wider variety of processing applications than vertical machining centers do; however, horizontal machining centers are more expensive than vertical machining centers. Users are encouraged to make decisions based on their own capabilities. 3. Mold machining centers that have linkage for more than three axes typically perform the processing of molds that have spatial surfaces. 4. The gantry machining center is typically utilized for the processing of large molds. 5. Machining centers capable of high speeds, which also have a good dust-proof performance and provide full protection. In general, electrode materials or graphite are used for the processing molds.
