The so-called yield strength of seamless steel pipe refers to the yield limit of seamless steel pipe when it yields, that is, the stress of slight plastic deformation. External forces beyond this limit will permanently disable the component and will not be restored.


The external factors affecting the yield strength of seamless steel tube are temperature, strain rate and stress state. With the decrease of temperature and the increase of strain rate, the yield strength of materials increases, especially the body-centered cubic metal is particularly sensitive to temperature and strain rate, which leads to low temperature embrittlement of steel. The effect of stress state is also important. Although yield strength is an important index of the inherent properties of materials, the yield strength values vary with the stress state.


The internal factors affecting the yield strength of seamless steel tubes are bonding, structure, and atomic properties. For example, by comparing the yield strength of metals with ceramics and polymers, it can be seen that the effect of bonding is fundamental.