Grain growth behaviour of an AISI 422 martensitic stainless steel after hot deformation process. (3rd July 2018)

• Record Type: Journal Article
• Authors: Mohammadi Ahmadabadi, Reza; Naderi, Malek; Aghazadeh Mohandesi, Jamshid; Cabrera, Jose Maria
• Is Part Of: Canadian metallurgical quarterly. Volume 57:Number 3(2018)
• Page Start: 367
• Page End: 379
• Publication Date: 2018-07-03
• Subjects: AISI 422 stainless steel -- softening fraction -- grain size -- hot deformation -- grain growth -- EBSD analysis; Metallurgy -- Periodicals; 669.05
• DOI: 10.1080/00084433.2018.1444414
• Languages: English
• ISSNs: 0008-4433

Abstract

ABSTRACT: The metadynamic softening behaviour and grain size refinement of an AISI 422 martensitic stainless steel in the temperature range of 950–1150°C was investigated by double-hit compression tests. The deformed specimens were held at deformation temperature with delay times of 5–300 s after achieving a strain of 0.3. Based on the experimental results, a model was established for estimation of a softening fraction at different deformation parameters, and the softening fraction was compared with a recrystallised fraction. A major deviation was observed at the beginning of interpass time denoting a significant contribution of recovery to the fractional softening (FS). However, by increasing the time and temperature, the difference between the FS and recrystallised fraction is reduced. The finer grain size was achieved by prior fine pre-austenite grain and lower secondary deformation temperature. The initial grain size of 53 µm decreased down to 32 and 19 µm at the deformation temperatures of 1020 and 940°C, respectively. The austenite grains have considerable growth at a temperature higher than 1020°C, while the grain coarsening is negligible at lower deformation temperatures.