ROLLING METHOD FOR SEAMLESS STEEL PIPE OF HIGH ALLOY STEEL

摘要

PURPOSE:To obtain a steel pipe having no flaw generation by performing rolling after heating an inside face at the lower temperature that the temperature rise by working is deducted from a specific rolling start temperature and heating the outer face at the specific rolling start temperature. CONSTITUTION:In the case of rolling a thick wall blank pipe, the inside face of the blank pipe is heated at the lower temperature that the temperature to be risen with the rolling is deducted from a preset rolling start temperature and the outer face is heated at the specific rolling start temperature. The work is started by heating the inner and outer faces at different temperatures. A high alloy seamless steel pipe of excellent external appearance having no flaw generation without causing a local molten brittleness phenomenon and an uniform wall thickness can be obtained.