J Mater Sci Technol ›› 2007, Vol. 23 ›› Issue (01): 0-117.

• Research Articles •     Next Articles

Hot Forging of Nitrogen Alloyed Duplex Stainless Steels

P.Chandramohan, S.S.Mohamed Nazirudeen, S.S.Ramakrishnan   

  1. Department of Mechatronics Eng, Sri Krishna College of Eng and Tech, Coimbatore 641008, India...
  • Received:2006-03-22 Revised:2006-07-24 Online:2007-01-28 Published:2009-10-10
  • Contact: P.Chandramohan

Abstract: Duplex stainless steels are gaining global importance because of the need for a high strength corrosion resistant material. Three compositions of this group were selected with three different nitrogen contents viz, 0.15 wt pct (alloy 1), 0.23 wt pct (alloy 2) and 0.32 wt pct (alloy 3). The steels were melted in a high frequency induction furnace and hot forged to various reductions from 16% to 62%. In this work, the effect of hot forging on the ferrite content, hardness, yield strength, impact strength and grain orientation (texture) were studied. Fracture analysis on all the forged specimens using SEM reveals that a size reduction of 48% results in maximum ductility and impact strength as well as minimal ferrite content and grain size. Thus the mechanical properties are found to have a direct correlation to ferrite content and grain size. The highest impact strength was observed in specimens with the smallest grain size, which was observed in specimens forged to 48% reduction in size.

Key words: Duplex, Austenite, Ferrite, Forging, Solutionizing