THE EFFECT OF ANNEALING ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF WELDED CARBON STEEL

Authors: Onwuamaeze I.P, *Oyejide J.O, Salisu S

DOI Info: N/A

ABSTRACT

This paper is focused on the investigation of the effect of annealing on the microstructure and mechanical properties of welded carbon steel. The properties put into consideration were strength, hardness, ductility, and microstructure examination of the sample with optical microscopy. Samples of the same grades of steel plates of 10mm diameters were used in this research work. The carbon content of the steel plates was 0.16 %wt. From each grade of steel materials, groove specimens of 250mm were prepared. The groove was filled to create welds using arc welding. The resulting welds were then subjected to annealing heat treatment. The strength values and ductility of the weld were determined. The microstructural analyses of the weld were carried out as well. The results show that ultimate tensile strength for the heat-treated specimen was 9355MN/m² and that of the untreated specimen was 10,327.27MN/m². The percentage ductility for heat treated specimen was 16% while the un treated specimen was 12%. There was also significant microstructural modification due to heat treatment. Therefore, for improvement in mechanical properties of carbon steel, annealing heat treatment is required.

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