500MPa-grade VN alloying non-tempering seamless steel tube and manufacturing method thereof

The invention provides a 500MPa strength grade VN alloying non-tempering seamless steel tube and a manufacturing method thereof. The seamless steel tube comprises the following components in percentage by weight: C: 0.28%-0.34%, Si: 0.32%-0.50%, Mn: 1.25%-1.45%, 0tempering seamless steel tube. The 500MPa strength grade VN alloying non-temperingseamless steel tube manufactured by the components and processes of method has excellent mechanical performance, and meets the performance requirement of the 500MPa-grade seamless steel tubes under non-tempering condition; and the vertical full-scale 0 DEG C impact work of the 500MPa strength grade VN alloying non-tempering seamless steel tube can reach above 65 J in average when the minimum yield strength reaches 500MPa.