PURPOSE: To produce the high-Ni alloy seamless pipe having the good outside surface quantity of the pipe without generating rolling flaws by using a round billet or square bloom of the high-Ni alloy formed with an aluminum film on the surface and forming the pipe by a Mannesmann rolling method.
CONSTITUTION: The melt of the high-Ni alloy smelted in an ordinary melting furnace, such as electric furnace or converter, is formed to the round billet or square bloom of a generally used shape by a continuous casting method or blooming method and thereafter, the surface thereof is coated with the aluminum film by an arbitrary method, such as plating method or thermal spraying method. The round billet or the like is thereafter heated to a high temp. and is made into the pipe product by the Mannesmann rolling method in which the billet or the like is made into a thick hollow blank pipe by a Mannesmann piercer and is finished by rolling pipe polishing machine and sizing mills, and further, by a reducing mill after reheating as necessary.
SOGO YASUO
MIZOGUCHI SHIGERU
TAKAGUCHI MITSURU
