Effect of Aging on the Microstructure and Mechanical Properties in Super Duplex Stainless Steel

J. Ocean Eng. Technol. 2009;23(3):40-45.

Kim Su-Chun,Kang Chang-Yong

Department of Physical Matellurgy Graduate School PuKyung National University,Div. of Advanced Materials Science & Engineering PuKyung National University

슈퍼 2상 스테인리스강의 미세조직 및 기계적 성질에 미치는 시효의 영향

김수천,강창룡

부경대학교 대학원,부경대학교 신소재공학부

Keywords: Duplex stainless steel, Aging, ${sigma}$ phase, Austenite phase, Ferrite phase

핵심용어: 2상스테인리스강, 시효, 시그마상, 오스테나이트 상, 페라이트 상

Abstract

With the increase in the annealing temperature, the volume fraction of austenite phase increased and the volume fraction of ferrite phase decreased. In compliance with the addition of N, not only the volume fraction of austenite phase was increased but also the austenite structure was made larger. Volume fraction of ${sigma}$ phase was increased by decreasing of the volume fraction of ferrite phase, with the increase in the aging time and in compliance with the addition of N. As increasing in volume fraction of ${sigma}$ phase, tensile strength and hardness increased, while elongation and impact value decreased. Elongation slowly decreased and impact value rapidly decreased at the early stage of aging. By the added N, tensile strength, elongation, hardness and impact value was increased.