Preparation of iron-containing sintered product

Abstract

Abstract PURPOSE: To provide a sintered product having high air tightness and large mechanical strength that has the surface part nitrided and hardened at a prescribed depth and pores sealed in the interior side, by steam-treating the sintered product of an iron-containing powder molded form before reduction-treating it and further by nitriding it. CONSTITUTION: Iron-containing powder-comprising nitrided steel containing, in particular, Al, Cr and Mo is pressure-molded into a powder molded form having a prescribed shape. Subsequently, the molded form is sintered in a burning furnace to prepare a sintered product. The sintered product is steam-treated to form iron oxides in the pore of sintered product, and thus pores all over the surface to the niterior are sufficiently sealed to improve the air tightness of the sintered product. Subsequently, the sintered product after the steam-treatment is reduction-treated to reduce iron oxides in pores to metallic iron and to open the sealed pores. Next, the reduction-treated sintered product is nitrided to form intrided structure of iron nitride base in the pores of the surface part, and thus the desired iron-containing sintered product is prepared. COPYRIGHT: (C)1982,JPO&Japio

Inventors

• 👤 Shuji Matsumoto

Bibliographic Details