Bimetallic Castings in a Chromium-Nickel Stainless Steel Working Surface Layer Configuration with a Grey Cast Iron Base

摘要

The paper presents the problem of obtaining a permanent diffusion joint between the working surface layer and the base part in a bimetallic casting. The bimetallic castings studied here were obtained as a result of using the founding method of layer coating directly in the cast process, i.e., the so-called method of mould cavity preparation by monolithic insert. The castings prepared using this method consist of two fundamental parts, i.e., the base which constitutes typical foundry material, i.e., grey cast iron and the working surface layer which constitutes plate of chromium-nickel stainless steels, X2CrNi 18-9 and X2CrNiMoN22-5-3 grade. On the basis of the obtained results it was confirmed that the decisive phenomena that are needed to create a permanent joint between the two components of the bimetallic casting are carbon and heat transport in the direction from the high-carbon and hot base material which was poured into the mould in the form of liquid metal to the low-carbon and cold material of the working layer which was placed in the mould cavity in the form of a monolithic insert.