Improving the Technology Used in Fabrication of Tube Bundles of Heat Exchangers Produced from 12Cr18Ni10Ti Steel by Means of Friction Welding

Abstract

12Cr18Ni10Ti steel is widely used in the production of heat exchangers that function under high temperatures in corrosive environments. The technological process involved in the production of heatexchanger tubes with tube plates from this brand of steel, which includes the use of arc welding, is greatly complicated by the need to carry out thermal operations to achieve the required operating properties of composite joints of 12Cr18Ni10Ti steel, including resistance to intercrystalline corrosion. Replacement of arc welding by rotary friction welding represents an effective means of eliminating thermal operations in the manufacture of the tube bundles incorporated into heat exchangers, though no data is currently available on the properties of welded joints produced from 12Cr18Ni10Ti steel by friction welding. An evaluation of the potentialthat may be gained with the use of friction welding to produce composite joints with analternative design is presented here. The structures of the metal are investigated and statictension and impact bend tests of specimens of 12Cr18Ni10Ti steel produced by friction welding carried out for this purpose.