The Quality of the Joint Between Alloy Steel and Unalloyed Cast Steel in Bimetallic Layered Castings

Abstract

In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer). The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic unalloyed cast steel, whereas working part (layer) is plate of austenitic alloy steel sort X2CrNi 18-9. The ratio of thickness between bearing and working part is 8:1. The aim of paper was assessed the quality of the joint between bearing and working part in dependence of pouring temperature and carbon concentration in cast steel. The quality of the joint in bimetallic layered castings was evaluated on the basis of ultrasonic non-destructive testing, structure and microhardness researches.

The Influence of Selected Cast Parameters on Quality of Joint in Layered Castings

“…Moreover as show in paper [17] the pouring temperature influences on degree of nonlinearity of boundary between the working part (layer) and the bearing part, which determines high strength of joint between both materials in bimetallic layered casting. Increases in nonlinearity of boundary in result from increase in pouring temperature of cast steel is observed.…”

“…Presence of so-called "bimetallic connecting bridges" also provides stability of joint between working and bearing part of bimetal in conditions of small load. A more detailed characterization of the so-called "bimetallic connecting bridges" is shown in paper [16].…”

“…The basic technology of layered castings is so-called method of mould cavity preparation in which the enriched element of the working surface layer of the casting is placed in mould in form of monolithic or granular insert directly before pouring molten metal [1][2][3][4][5][6][7]. This technology is the most economical way of enrichment the surface of castings, as it allows the production of layer elements directly in the process of cast.…”