Tensile strength and yield strength of pipeline steel is steel chemical composition and rolling process of the decision. Gas pipeline material selection, should be used with higher yield strength steels to reduce the amount of steel. However, the higher the yield strength is not better. Yield strength is too high will reduce the toughness of the steel.
After repeated tensile steel in compression, the mechanical properties will change, lower intensity, severe reduced by 15%, or Bauschinger effect. Steel tubes in the order system, this factor must be considered. Can be taken at the level of the minimum yield strength of steel on the basis of increased 40-50MPa. Election should be considered when steel yield strength and tensile strength of steel in the ratio between the - yield ratio to ensure the quality of pipe forming and welding performance.