| 摘要 |
PURPOSE:To prevent a large crack and a small rash flaw from generation by heating and piercing a billet of deeplex stainless steel material at a specified temperature. CONSTITUTION:The relation between the heating temperature of duplex stainless steel material to be used in manufacture and the ferrite phase division percentage is researched in advance. Since the relation between the ferrite division percentage and the heating temperature tends to vary with component difference, it is necessary to research the relation in advance for the purpose of obtaining the optimum heating temperature. Therefore, the heating temperature in a phase division percentage 80 % of ferrite is obtained. When a seamless tube is manufactured by the Mannesmann piercing process, etc., in a state of the temperature, a fine rash flaw and a large crack can be prevented from generation. |
