Manufacturing method of super high pressure seamless alloy steel pipe

The invention discloses a manufacturing method of a super high pressure seamless alloy steel pipe. The method mainly comprises steel bar and steel ingot smelting and manufacturing, steel bar forging, steel bar deep hole processing, steel bar thermal treatment and machining as well as steel bar cold drawing and spinning rolling. The method is characterized in that the steel bar and steel ingot smelting and manufacturing process comprises that alloying elements and original ecological steel scrap are selected as raw materials, EF smelting, LF refining, VD refining and vacuum degassing are performed sequentially, and smelting is performed to obtain AISI4333M4 steel. The components include 0.30%-0.38% of C, 0.70%-1.00% of Mn, 0.15%-0.35% of Si, 1.62%-2.00% of Ni, 0.70%-0.90% of Cr, 0.35%-0.45% of Mo, 0%-0.015% of P, 0%-0.005% of S, 0%-0.15% of Cu, 0%-0.005% of Pb, 0%-0.02% of Sn, 0%-0.009% of As, 0%-0.005% of Sb, 0%-0.005% of Bi, 0.02%-0.04% of Al, 0ppm-2ppm of H, 0ppm-2ppm of O and the balance of Fe. The manufacturing method of the super high pressure seamless alloy steel pipe has the advantages of high precision and excellent mechanical properties of the manufactured super high pressure seamless alloy steel pipe.