The yield strength of the seamless steel pipe refers to the yield limit of the seamless steel pipe when the yield phenomenon occurs, that is, the stress that resists the slight plastic deformation. External forces greater than this limit will cause the parts to fail permanently and cannot be recovered.
The external factors that affect the yield strength of seamless steel pipes are: temperature, strain rate, and stress state. With the decrease of temperature and the increase of strain rate, the yield strength of the material increases, especially the body-centered cubic metal is particularly sensitive to temperature and strain rate, which leads to the low temperature embrittlement of steel. The effect of stress state is also important. Although yield strength is an essential index reflecting the intrinsic properties of materials, the yield strength values are also different for different stress states.
The intrinsic factors that affect the yield strength of seamless steel pipes are: bond, organization, structure, and atomic nature. For example, by comparing the yield strength of metals with ceramics and polymer materials, it can be seen that the influence of bonds is fundamental.