Anew HIP and hot extrusion (HHE) process for manufacturing bimetallic pipes and tubes is proposed. The purpose is to produce bimetallic pipes and tubes the liner and substrate of which consist of those having a large difterence in their hot deformation resistances. The most important point is to join the two metals metallurgically, by hot isostatic pressing, before hot working such as hot extrusion. After the feasibility of the process had beenverified bythe preliminary study at a laboratory

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... le, a trial production was conducted for a full scale corrosion resistant pipe for oil country tubular goods (OCTG) for sourservice. Theinner and outer materials of the pipe were a nickel-base superalloy and SSC resistant low alloy high strength steel, respectively. A bimetallic pipe with uniforhl thickness of both outer and inner metals was obtained by the new process. The corrosion resistance of the two layers of metals as well as the strength of the outer material exhibited satisfactory performance to comply with the requirements forOCTGuse. Theproposed process, HIP and hot extrusion process, is promising for producing bimetallic materials with excellent corrosion resistance and with metallurgical bonding betweentwo materials that have much different hot workabilities.