What is the effect of the mold material on the heat treatment deformation? The influence of the material on the heat treatment deformation, including the chemical composition of the steel and the original structure. From the material itself, the heat treatment deformation is mainly affected by the influence of the composition on the hardenability, the Ms point, and the like. When the carbon tool steel is subjected to water-oil two-liquid quenching at normal quenching temperature, it generates a large thermal stress above the Ms point;
when it is cooled below the Ms point, the austenite transforms to martensite and generates tissue stress, but Since the carbon tool steel has poor hardenability, the value of the tissue stress is not large. In addition, the Ms point is not high. When the martensite structure changes, the plasticity of the steel is already poor, and plastic deformation is not easy. Therefore, the deformation characteristics caused by the thermal stress are retained, and the mold cavity tends to shrink. However, if the quenching temperature is increased (\u0026gt;850 °C), it may also be due to the fact that the tissue stress plays a leading role, and the cavity tends to swell. For some high-alloy steels, such as Cr12MoV steel, due to its high carbon and alloying elements, the Ms point is lower, so there is more retained austenite after quenching, which has basket moulding https://www.haohaomould.com/product/chair-box-basket-container-mould/ a volume expansion due to martensite. Offset, therefore, the deformation after quenching is quite small, generally when air quenching, air cooling, nitrate bath quenching, the mold cavity tends to slightly expand; if the quenching temperature is too high, the amount of retained austenite increases, type The cavity may also shrink. The original structure of the steel also has a certain influence on the quenching deformation.
The term ’original structure of steel’ as used herein includes the grade of inclusions in steel, the level of banded structure, the degree of segregation of components, the directionality of free carbide distribution, and the like, as well as the different tissues obtained by different preheat treatments ( Such as pearlite, tempered sorbite, tempered troostite, etc.). For die steel, the main considerations are carbide segregation, carbide shape and distribution.
when it is cooled below the Ms point, the austenite transforms to martensite and generates tissue stress, but Since the carbon tool steel has poor hardenability, the value of the tissue stress is not large. In addition, the Ms point is not high. When the martensite structure changes, the plasticity of the steel is already poor, and plastic deformation is not easy. Therefore, the deformation characteristics caused by the thermal stress are retained, and the mold cavity tends to shrink. However, if the quenching temperature is increased (\u0026gt;850 °C), it may also be due to the fact that the tissue stress plays a leading role, and the cavity tends to swell. For some high-alloy steels, such as Cr12MoV steel, due to its high carbon and alloying elements, the Ms point is lower, so there is more retained austenite after quenching, which has basket moulding https://www.haohaomould.com/product/chair-box-basket-container-mould/ a volume expansion due to martensite. Offset, therefore, the deformation after quenching is quite small, generally when air quenching, air cooling, nitrate bath quenching, the mold cavity tends to slightly expand; if the quenching temperature is too high, the amount of retained austenite increases, type The cavity may also shrink. The original structure of the steel also has a certain influence on the quenching deformation.
The term ’original structure of steel’ as used herein includes the grade of inclusions in steel, the level of banded structure, the degree of segregation of components, the directionality of free carbide distribution, and the like, as well as the different tissues obtained by different preheat treatments ( Such as pearlite, tempered sorbite, tempered troostite, etc.). For die steel, the main considerations are carbide segregation, carbide shape and distribution.
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