DEVELOPMENT OF HIGH CARBON-LOW NICKEL STAINLESS STEEL CONTAINING DIFFERENT MANGANESE CONTENTS

Hamed, O. A.; El- Desouky, A. R.; Hawash, M. S.; Farahat, A. I. Z.

doi:10.21608/erjm.2010.67338

DEVELOPMENT OF HIGH CARBON-LOW NICKEL STAINLESS STEEL CONTAINING DIFFERENT MANGANESE CONTENTS

Document Type : Original Article

Authors

¹ Department of Mechanical Design and Production Engineering, Faculty of Engineering, Minoufiya University, Egypt

² Central Metallurgical R&D Institute, CMRDI, Helwan, Egypt.

10.21608/erjm.2010.67338

Abstract

The production of low nickel austenitic stainless steel has increased considerably mainly due to nickel price evolution in the last years. Manganese steels exhibit the best combination of strength and ductility over the whole range of ductile steel grades for car manufacturing. But austenitic stainless steel containing manganese suffers from sigma phase and the material would be subjected to brittle fracture. Carbon decreases the sigma phase formation. However, carbon deteriorates the ductility of austenitic stainless steel. Therefore it was important to study the high temperature deformation of austenitic stainless steel containing manganese with low nickel. This paper is a trial to process austenitic stainless steel with manganese content ranging from 4.35 to 9.27 wt. %. The high temperature deformation was in range 950°C to 1200°C to prevent the hot formability with severe cracks. The tensile strength and hardness increase as the Mn content increases after thermomechanical treatment. The high deformation temperature accelerates the dynamic recrystallization of Fe-Mn steels leading to fine grains. The ferrite phase increases as the Mn contents increases after thermomechanical treatment. Sigma phase after thermomechanical deformation disappears and the final microstructure is fully austenitic with thin carbide on the grain boundaries. At 9 wt. % Mn content chromium carbide cannot be controlled and deteriorates the strength and ductility.

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