The Method of Overlay Welding Strengthening on the Surface of the Piercing Machine of Seamless Steel Pipe

Abstract

The invention discloses a method for strengthening the surface of the plug of a seamless steel pipe piercing machine by surfacing welding. The plug can be a casting or a forging. Firstly, the plug blank is subjected to initial machining, the head of the plug is cut to obtain the thickness of the surfacing welding, and the body parts are reserved for finishing. Allowance; for conventional flaw detection treatment, there are defects and rework treatment; use Ni-based, Co-based or cermet alloy materials to surfacing the head of the plug to form a surfacing layer and adopt the plasma arc surfacing method to ensure that the surfacing layer and the head of the plug The substrate is fully fused; the plug is turned to the final size requirement and flaw detection is performed, and defects are reworked; the surface of the plug is thermally oxidized to form an oxide film. The method can significantly increase the surface strength of the plug, improve the performance of the plug, reduce the production cost of the plug, increase the service life of the plug, and ensure the rolling quality of the seamless steel pipe.

Description

technical field [0001] The invention relates to a method for strengthening the surface of a seamless steel pipe piercer by overlay welding. Background technique [0002] The piercing machine plug is an important part of making seamless steel pipes. It is mainly used for the top hole of steel pipes in the production process of rolling seamless steel pipes. The plug is mainly composed of castings, and its shape is similar to a bullet. During the production process, the plug is subjected to the synergistic effect of high temperature, large rolling force, high friction and wear, and multiple cold and heat fatigue, resulting in a reduced service life, a large number of uses, and high consumption costs. Under the working conditions of high temperature, high pressure and high friction, the plug shows various failure modes such as flat nose of the plug head, adhesion peeling, fatigue cracking, etc. The failed plug seriously affects the rolling quality of the seamless steel pipe. In...

AI Technical Summary

Problems solved by technology

During the production process, the plug is subjected to the synergistic effect of high temperature, large rolling force, high friction and wear, and multiple cold and heat fatigue, resulting in a reduced service life, a large number of uses, and high consumption costs

Under the working conditions of high temperature, high pressure and high friction, the plug shows various failure modes such as flat nose of the plug head, adhesion peeling, fatigue cracking, etc. The failed plug seriously affects the rolling quality of the seamless steel pipe

In order to reduce the failure of the plug and improve the service life of the plug, improvements are mainly made from the following aspects: the first is to improve the performance of the plug by changing the chemical composition of the plug material, and this method generally adjusts the ratio of alloying elements This method increases the production cost of the plug, and the improvement ability is limited; the second is to improve the service life of the plug by adjusting the size or shape structure of the plug, but its improvement ability is also limited; the third is to improve the plug. Manufacturing process, improving the casting plug to forging plug can increase the density of the plug to improve its service life, but the cost of forging process is higher than that of casting process, so there is a disadvantage of high cost

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