Stainless steel head due to the surface and the heart of the cooling rate and time of the inconsistency, thermal stress. Stainless steel head under the action of thermal stress to make the workpiece surface pressure and the heart of the stretch. This phenomenon is affected by cooling rate, material composition and heat treatment process and other factors.
In the process of heat treatment, the change of the volume of the workpiece is caused by the change of the volume of the workpiece due to the change of the organization, that is, the transformation of the austenite to the martensite. The change of the volume of the workpiece is caused by the change of the volume of the workpiece.
The ultimate result of the stress change of the stainless steel head is the tensile stress of the surface layer, the compressive stress of the heart, and the opposite of the thermal stress. The size of the tissue stress is related to the cooling rate, shape, chemical composition of the workpiece in the martensitic transformation zone.
Thermal stress has produced a stainless steel head before the transformation of the organization, and the tissue stress is generated during the process of tissue transformation. The result of the combined effect of thermal stress and tissue stress during the whole cooling process is the actual stress in the workpiece The The combined effect of these two stresses is very complex and is influenced by many factors such as composition, shape, heat treatment and so on. There are only two types of developmental processes, namely, thermal stress and tissue stress, the opposite direction of action when the two offset, the role of the same direction when the two are superimposed on each other.
Source: China Stainless Steel Head Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)