PRESSURE TREATMENT OF METALS IMPROVING THE PRODUCTION OF CORROSION-RESISTANT STEEL PIPE ON AN 8-16' ROLLING UNIT WITH PILGER MILLS

摘要

The proposed measures permit: the production of large- and moderate-diameter commercial pipe and intermediate pipe products from hard-to-deform corrosion-resistant steel in the form of electrosmelted ingots on the 8-16" pipe-rolling unit with pilger mills at ChTPZ; piercing of the ingots and production of high-quality sleeve by an optimal technology (heating in continuous furnaces, piercing, and rolling on pilger mills); reduction in longitudinal wall-thickness fluctuation by rolling on less-tapered mandrels; reduction in metal consumption thanks to the use of carbon backing rings; reduction or elimination of internal-defect (bubble, crack) formation by rolling on heated mandrels; and considerable reduction in the probability of mandrel jamming in the pipe by producing a more oval profile in the deformation source, by greater reduction, and also by rolling on heated mandrels. These measures result in the production of high-quality commercial pipe (corresponding to Ail-Union State Standards GOST 9940 and 9941), as well as intermediate pipe products for nuclear plants (Technical Specifications TU 14-3-197-2001), and considerably reduce the metal consumption in processing electrosmelted ingots.