A plug with high perforation life and its manufacturing method

Abstract

The invention discloses a jackscrew with long perforation life. The jackscrew comprises the following chemical elements in percentage by mass: 0.15-0.25% of C, 0.30-0.70% of Si, 0.30-1.00% of Mn, 0.75-1.00% of Cr, 2.50-4.50% of Ni, 0.10-0.60% of Mo, 0.05-0.20% of Nb, 0.10-0.30% of V, 0.005-0.030% of Ti, 0.015-0.040% of Al, and the balance of Fe and other inevitable impurities; an oxide film covering a basal body is formed on the surface of the jackscrew; and the oxide film is provided with a lot of combination contacts formed by Nb and inserted into the basal body. In addition, the invention further discloses a preparation method of the jackscrew with long perforation life. The perforation life of the jackscrew is prolonged by 100-150% compared with a traditional jackscrew.

Description

technical field [0001] The invention relates to a plug and a manufacturing method thereof, in particular to a perforated plug and a manufacturing method thereof. Background technique [0002] The plug is one of the important tools with large consumption in the production of seamless steel pipes. Its main function is to form a closed cavity with the perforated roller and the guide plate to realize the transformation from the solid tube blank to the hollow capillary tube. [0003] During the piercing process, the plug bears great axial, tangential and radial forces and friction, and bears the high temperature caused by the tube blank and frictional heat (the temperature near the surface of the nose plug can reach 1100-1200 ° C, the piercing cone The temperature near the surface of the segment head is higher than the austenitization temperature), so it is very easy to damage the surface and fail during the piercing process. This failure is mainly related to the failure of the ...

AI Technical Summary

Problems solved by technology

The technical solution disclosed in this patent document uses relatively high Mo, W and rare earth Ce, so the alloying cost is high, and it is not conducive to the formation of an oxide film with good bonding force on the surface of the plug. At the same time, the low Ni content is also not conducive to the inside of the oxide film. The bonding force is improved, and the addition of Al will easily lead to an excessively high content of inclusions and reduce the thermal fatigue resistance of the plug

[0007] The design of the plug components involved in the technical solutions disclosed in the above-mentioned patent documents does not solve the problem of how to form an oxide film with a strong bond with the substrate on the outer surface of the plug under high-temperature oxidation heat treatment conditions

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