Abstract
Metastable austenitic stainless steels undergo deformation induced transformation to bcc martensitic structure during cold-working. The martensite induced reverts to austenite at a relatively low temperature and this leads to the formation of ultra fine austenite grains of less than 1 μm in diameter. In this paper, the effect of pre-cold-working on the morphology of reversed austenite was investigated by means of transmission electron microscopy and tensile test. The alloy used is an Fe-18.08%Cr-8.65%Ni alloy. Since this alloy has metastable austenitic structure at room temperature, it almost transforms to lath-martensite by 50% cold-rolling. Further cold-rolling above 50% deforms transformed martensite itself, and results in the formation of dislocation-cell structure instead of lath-martensitic structure. The diffusional reversion of deformation induced martensite takes place at around 900 K and pre-cold-working to lath-martensite not only promotes the reversion but also gives a large effect on the microstructure of reversed austenite: Reversed austenite is characterized, in a specimen with 50% pre-cold-working, by the stratum structure of austenite laths and blocks, which looks like a lath-martensitic structure, while in a specimen with heavy pre-cold-working, by the structure of fine equiaxed grains. On the discussion of grain boundary strengthening in the former case, 0.2% proof stress depends not on the lath size but on the block size of reversed austenite.
| Original language | English |
|---|---|
| Pages (from-to) | 522-527 |
| Number of pages | 6 |
| Journal | isij international |
| Volume | 34 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jan 1 1994 |
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All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry
Cite this
Effect of Pre-cold-working on Diffusional Reversion of Deformation Induced Martensite in Metastable Austenitic Stainless Steel. / Takaki, Setsuo.
In: isij international, Vol. 34, No. 6, 01.01.1994, p. 522-527.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of Pre-cold-working on Diffusional Reversion of Deformation Induced Martensite in Metastable Austenitic Stainless Steel
AU - Takaki, Setsuo
PY - 1994/1/1
Y1 - 1994/1/1
N2 - Metastable austenitic stainless steels undergo deformation induced transformation to bcc martensitic structure during cold-working. The martensite induced reverts to austenite at a relatively low temperature and this leads to the formation of ultra fine austenite grains of less than 1 μm in diameter. In this paper, the effect of pre-cold-working on the morphology of reversed austenite was investigated by means of transmission electron microscopy and tensile test. The alloy used is an Fe-18.08%Cr-8.65%Ni alloy. Since this alloy has metastable austenitic structure at room temperature, it almost transforms to lath-martensite by 50% cold-rolling. Further cold-rolling above 50% deforms transformed martensite itself, and results in the formation of dislocation-cell structure instead of lath-martensitic structure. The diffusional reversion of deformation induced martensite takes place at around 900 K and pre-cold-working to lath-martensite not only promotes the reversion but also gives a large effect on the microstructure of reversed austenite: Reversed austenite is characterized, in a specimen with 50% pre-cold-working, by the stratum structure of austenite laths and blocks, which looks like a lath-martensitic structure, while in a specimen with heavy pre-cold-working, by the structure of fine equiaxed grains. On the discussion of grain boundary strengthening in the former case, 0.2% proof stress depends not on the lath size but on the block size of reversed austenite.
AB - Metastable austenitic stainless steels undergo deformation induced transformation to bcc martensitic structure during cold-working. The martensite induced reverts to austenite at a relatively low temperature and this leads to the formation of ultra fine austenite grains of less than 1 μm in diameter. In this paper, the effect of pre-cold-working on the morphology of reversed austenite was investigated by means of transmission electron microscopy and tensile test. The alloy used is an Fe-18.08%Cr-8.65%Ni alloy. Since this alloy has metastable austenitic structure at room temperature, it almost transforms to lath-martensite by 50% cold-rolling. Further cold-rolling above 50% deforms transformed martensite itself, and results in the formation of dislocation-cell structure instead of lath-martensitic structure. The diffusional reversion of deformation induced martensite takes place at around 900 K and pre-cold-working to lath-martensite not only promotes the reversion but also gives a large effect on the microstructure of reversed austenite: Reversed austenite is characterized, in a specimen with 50% pre-cold-working, by the stratum structure of austenite laths and blocks, which looks like a lath-martensitic structure, while in a specimen with heavy pre-cold-working, by the structure of fine equiaxed grains. On the discussion of grain boundary strengthening in the former case, 0.2% proof stress depends not on the lath size but on the block size of reversed austenite.
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U2 - 10.2355/isijinternational.34.522
DO - 10.2355/isijinternational.34.522
M3 - Article
AN - SCOPUS:0028062392
VL - 34
SP - 522
EP - 527
JO - ISIJ International
JF - ISIJ International
SN - 0915-1559
IS - 6
ER -