Corrosion-resistant dual metal clad tube blank and manufacturing method thereof

Abstract

A manufacturing method of a corrosion-resistant dual metal clad tube blank comprises the following steps: outer-layer molten metal is pumped into a pipe die for centrifugal pouring, the molten metal is cooled after pouring, and inner-layer molten metal is poured when internal surface temperature of the outer layer is cooled to be lower than 50-70 DEG C which is the melting point of the outer-layer molten metal; inner-layer molten metal is pumped into the pipe die for centrifugal pouring, the molten metal is cooled after pouring; cooling is stopped after the outer layer and the inner layer are completely solidified, at the moment, the inner layer and the outer layer achieve complete metallurgical bonding; wherein, the outer layer is made of X52 or X60 steel and the inner layer is made of 825 steel. A metallurgical bonding layer of a production tube obtained by carrying out extrusion or hot rolling on the tube blank manufactured by the method is several times or dozens of times as thick as a bonding layer of the dual metal tube obtained by the explosive welding process; the transition of the ingredients on the inner and outer layers is gentle, thus greatly relieving the interfacial stress between the inner layer and the outer layer, facilitating the inner layer and the outer layer not to be layered easily, improving the safety of the use of the production tube and prolonging the service life of the production tube.

Description

technical field [0001] The invention relates to a corrosion-resistant bimetal composite material, in particular to a corrosion-resistant bimetal composite tube blank and a production method thereof. The tube blank is processed into a corrosion-resistant bimetal seamless finished tube by extrusion or rolling. Background technique [0002] X52 / 825, X60 / 825 bimetallic pipes are mainly used for oil well pipes and manifold pipes of highly corrosive oil and gas wells. X52 and X60 are two strength levels in the American API (American Petroleum Institute) standard, referring to all steel materials that meet the performance requirements of Table 1 and Table 3. 825 is a corrosion-resistant nickel-based alloy material. It is the grade UNS N08825 in the American ASTM, ASME, and AMS standards. It is equivalent to NA16 in the British standard BS and NiFe30Cr21Mo3 in the international standard ISO. 2 For oil and gas fields with high S content, see Table 2 for its composition requirements....

AI Technical Summary

Problems solved by technology

However, the X52 / 825 and X60 / 825 bimetal composite pipes formed by this process cannot guarantee that the inner and outer layers are completely welded, and there will always be some unwelded areas. During use, these unwelded areas will be damaged. Gradually expand, eventually causing delamination of the inner and outer layers, affecting the safety of bimetallic pipes

In addition, the thickness of the fusion layer formed by explosive welding is only a few microns. In the harsh environment, due to the difference in the material of the inner and outer layers, the stress concentration at the interface between the very thin inner and outer layers will result in a large interface stress. Stress promotes internal and external delamination, which also affects the safety of pipelines

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