Reverse Schemes of Explosive Cladding of Long-Length Pipe Billets

Abstract

The present work is aimed at solving an important problem: premature failure of a critical element of downhole equipment, such as the pump-compressor pipe. For performance improvement, we propose to clad the inner part of the steel pipe with stainless steel. We experimentally test three schemes of explosive cladding by stainless steel of the inner part of one-meter steel pipe billets. For the production of high-quality twolayer pipes by explosion welding, we also propose to use either solid (a metal rod) or solid-liquid (shots with water) internal fillers. The use of these types of fillers makes it possible to avoid damage to the inner cladding layer and minimize the transverse deformation of the bimetallic pipe. Microstructural analysis of the joint boundary shows that the proposed explosion cladding produces an acceptable joining of the 37Mn2V structural steel with the 08Cr18Ni10Ti corrosion-resistant steel. The shock-compressed gas in the welding gap with no lateral outflows is found to lead to the formation of large fusion zones on the final sections of bimetallic cylindrical billets that may result in delamination of the layer joint. The quality of the welded two-layer tube blanks is ultrasonically controlled to check the bond continuity. Verification indicates that the adhesion of layers of good quality occurs over the entire length of samples, except for small initial and final segments.