In the mold production cost, the material cost generally accounts for 10%~20%, while mechanical processing, heat treatment, assembly and management expenses account for more than 80%, so.
The process performance of the mould is one of the main factors that affect the production cost and manufacturing difficulty.
-- thermal processing property, refers to thermoplastic, processing temperature range, etc.;
-- cold working performance, refers to cutting, grinding, polishing, cold drawing and other processing performance.
The cold working die steel is mostly in the steel, the heat processing and the cold processing properties are not very good, so the hot processing must be strictly controlled.
And cold machining process parameters to avoid defects and rejects. On the other hand, by improving the purity of steel and reducing the content of harmful impurities,
Improve the structure of the steel to improve the hot and cold processing properties of the steel, thus reducing the production cost of the die.
In order to improve the cold machining performance of die steel, since the 1930s, it has been studied to add S, Pb, Ca, Te and other easy cutting addition to die steel.
Working elements or graphite elements that lead to carbon in die steels have developed a variety of free-cutting die steels to further improve their cutting performance and grinding.
Can, reduce tool abrasive consumption, reduce cost.
The hardenability mainly depends on the chemical composition of steel and the state of the original tissue before quenching. The hardening depends mainly on the carbon content in the steel. for
Most of the cold die steel, hardening is often one of the main considerations. For hot die steel and plastic mold steel, general mold size.
It is more important to make large moulds, especially for large moulds. In addition, for various moulds that can easily produce heat treatment deformation,
In order to reduce the quenching deformation, the quenching medium with weak cooling capacity is often used as far as possible, such as air cooling, oil cooling or salt bath cooling, in order to obtain the requirements.
The hardness and depth of hardened layer need to be made of hardened steel.
In order to facilitate production, the quenching temperature range of die steel is required to be as relaxed as possible, especially when the mold is heated by flame.
Because it is difficult to measure and control the temperature accurately, it is required to have a wider quenching temperature range.
During heat treatment, especially during quenching process, it is necessary to produce volume change, shape warping, distortion, etc., to ensure the quality of mould.
The heat treatment deformation of die steel is small, especially for the precision mould with complicated shape, it is difficult to repair after quenching, and it is necessary for the deformation degree of heat treatment.
To be more demanding, we should choose micro - deformation die steel.