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Pressed ventilation elbow is treated differently
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Pressed ventilation elbow is treated differently

During the heating and cooling process of the Pressed ventilation elbow, due to the inconsistency of the cooling speed and time between the surface layer and the core, a temperature difference is formed, which will lead to uneven expansion and contraction of the volume and generate stress, that is, thermal stress. Under the action of thermal stress, since the initial temperature of the surface layer is lower than that of the core, the contraction is also greater than that of the core, and the core is stretched. pulled. That is, under the action of the thermal stress of the carbon steel Pressed ventilation elbow, the surface of the workpiece is finally compressed and the core is pulled. This phenomenon is affected by factors such as cooling rate, material composition and heat treatment process. When the cooling rate is faster, the carbon content and alloy composition are higher, the carbon steel Pressed ventilation elbow, the greater the uneven plastic deformation under the action of thermal stress during the cooling process, the greater the residual stress formed later.

Pressed ventilation elbow

On the other hand, in the process of heat treatment of carbon steel Pressed ventilation elbow steel, due to the change of structure, that is, the transformation of austenite to martensite, the increase of specific volume will be accompanied by the expansion of the volume of the workpiece, and the various parts of the workpiece will undergo phase transformation, resulting in a long volume. Large inconsistencies result in tissue stress. The final result of the change of tissue stress is tensile stress on the surface and compressive stress on the core, which is just the opposite of thermal stress. The size of the structural stress is related to the cooling rate, shape, chemical composition of the material and other factors of the workpiece in the martensitic transformation zone.