Effect of continuous cooling heat treatment on interface characteristics of S45C/copper compound casting

The bonding of an S45C steel insert to copper during cast welding and continuous cooling treatment (including: furnace cooling; air cooling; oil quenching and water quenching) was investigated. The interface shear strength was determined using a push-out test. A cast welding layer formed between S45C steel and copper. After continuous cooling heat treatment, a cast welding layer was present near the S45C steel, an irregular layer near the copper matrix, and a middle layer between these two. X-ray diffraction analysis was used to determine that the interface layer consisted of carbon and CuFeO₂.Electron probe microanalysis (EPMA) demonstrated that most iron atoms and carbons diffused into the copper matrix. The interface shear strength of the compound casting under furnace-cooling was the largest and that of the compound casting formed by water-quenching was the smallest, and all fractures in the cast welding layer occurred near the S45C steel matrix.