OXY-ACETYLENE DIFFUSION WELDING OF PLAIN CARBON STEELS

DARWISH, A. H.; ABDOU, M. A.; EL-GEMAE, S. H.; MORSY, A. A.

doi:10.21608/amme.1984.49189

OXY-ACETYLENE DIFFUSION WELDING OF PLAIN CARBON STEELS

Document Type : Original Article

Authors

¹ Professor, Mechanical Engineering Department, AL-Azhar University Nasr City, Cairo. Egypt.

² Associate professor, Mechanical Engineering Department, AL-Azhar University Nasr City, Cairo. Egypt.

³ Research Assistant, Mechanical Engineering Department, AL-Azhar University Nasr City, Cairo. Egypt.

10.21608/amme.1984.49189

Abstract

A simple practical method for diffusion welding of steel components, in air, was developed. Specially designed oxy-acetylene ring burner was used for heating the specimens up to 1273 K. Two main advantages could be gained by using the designed burner. Firstly, very short heating up times were obtained. Secondly, the reducing zone of the oxy-acetylene flame was used as a protective atmosphere during the welding process. A series of plain carbon steel specimens ranging from 0.17% C to 1.1% C were, successfully, diffusion welded in air. A thin carbon rich layer was wrapped around the specimen at the periphery of the welding zone to act as a sealing ring and reduce oxidation. The specimens were heat treated and microhardness, impact, bending and tensile tests were conducted. The yield strength of the welded joints was found to decrease with increasing carbon content up to the eutectoid composition. However, above 0.8%C the yield strength increased with increasing carbon content. Metallographic examinations of the diffusion welded joints revealed the existence of ferritic bands close to the welding interface. The observed microstructure features were correlated with the differences in strength of various steels.