Effect of Copper on the Crystallization Process, Microstructure and Selected Properties of CGI

Abstract

The paper presents the results of the research on the effect of copper on the crystallization process, microstructure and selected properties of the compacted graphite iron. Compacted graphite in cast iron was obtained using Inmold process. The study involved the cast iron containing copper at a concentration up to approximately 4%. The effect of copper on the temperature of the eutectic crystallization as well as the temperature of start and finish of the austenite transformation was given. It has been shown that copper increases the maximum temperature of the eutectic transformation approximately by 5C per 1% Cu, and the temperature of the this transformation finish approximately by 8C per 1% Cu. This element decreases the temperature of the austenite transformation start approximately by 5C per 1% Cu, and the finish of this transformation approximately by 6C per 1% Cu. It was found that in the microstructure of the compacted graphite iron containing about 3.8% Cu, there are still ferrite precipitations near the compacted graphite. The effect of copper on the hardness of cast iron and the pearlite microhardness was given. This stems from the high propensity to direct ferritization of this type of cast iron. It has been shown copper increases the hardness of compacted graphite iron both due to its pearlite forming action as well as because of the increase in the pearlite microhardness (up to approx. 3% Cu). The conducted studies have shown copper increases the hardness of the compacted graphite iron approximately by 35 HB per 1% Cu.

A Study on Reduction of Copper Smelting Slag by Carbon for Recycling into Metal Values and Cement Raw Material

“…Carbon from reducing agent can be formed to inform of iron carbide in the ferrous alloy during reduction smelting for the recovery of iron from copper slag. Copper is used as an additive element to improve mechanical properties such as hardness, abrasion resistance and corrosion resistance in cast iron products [17,18].…”

Optimizing the Gating System for Steel Castings

“…The authors of [19][20][21] thoroughly described the outstanding properties of the CGI iron while comparing it with the Ductile Iron (DI). The properties of the modern ADI grades and their capability to replace the steel castings in some applications have been presented in [22,23]. Yearly production of steel castings oscillates at ca.…”

Selected Phenomena of the In-Mold Nodularization Process of Cast Iron That Influence the Quality of Cast Machine Parts

“…Their low density causes them to flow to the surface layer of the casting, thus reducing its quality. It thus seems obvious that sulfur in cast iron should be eliminated or reduced to a minimum during the nodularization process in mold; however, authors [9][10][11][12][13][14] noted that there is a certain minimum amount of sulfur in cast iron that is required to produce cast iron of an adequate quality due to the correct morphology of graphite precipitates. The authors [1] showed the production process of cast iron castings with vermicular graphite precipitates, where sulfur compounds were deliberately added into the liquid alloy.…”