Evolution of Microstructure and Oxidation Layer of 430 Stainless Steel During Hot Rolling

2011 ◽  
Vol 194-196 ◽  
pp. 316-320
Author(s):  
Lian Hong Yang ◽  
Ya Zheng Liu ◽  
Le Yu Zhou ◽  
Long Jiao Li
Keyword(s):  
Stainless Steel ◽  
Hot Rolling ◽  
Experimental Result ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Oxidation Layer ◽  
Deformation Amount ◽  
430 Stainless Steel ◽  
Evolution Of Microstructure

OM, SEM, TEM and XRD were used to analyze microstructure and oxidation layer of 430 stainless steel during hot rolling, and microstructure characteristic and oxidation layer evolution rule under high temperature deformation were studied. It is shown that microstructure after each pass under laboratory rolling condition is composed of austenite and ferrite, but there are significant differences in the size, morphology and distribution of dual phase microstructure. Oxidation layer of each pass consists mostly of Fe2O3, Fe3O4 and FeCr2O4. Thickness of surface oxide film decreases from 12μm to about 4~5μm as rolling pass increases. Compared to experimental result of laboratory rolling, because high-pressure descaling is used in practical production, meanwhile deformation amount is higher and surface quality of roller is better, oxidation layer of finished product is uniform, distributes continuously and has strong internal bonding force with matrix.

Effect of Residual Stress on High Temperature Deformation in a Weld Stainless Steel

2006 ◽  
Vol 524-525 ◽  
pp. 311-316 ◽  
Author(s):  
Robert C. Wimpory ◽  
Farid R. Biglari ◽  
Rainer Schneider ◽  
Kamran M. Nikbin ◽  
N.P. O'Dowd
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Imperial College ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Collaborative Effort ◽  
Specific Objective ◽  
Before And After

This paper considers the measurement of residual stresses induced by mechanical loading in a weld Type 347 stainless steel. The work is based in part on an ongoing Round Robin collaborative effort by the Versailles Agreement on Materials and Standards, Technical Working Area 31, (VAMAS TWA 31) working on ‘Crack Growth of Components Containing Residual Stresses’. The specific objective of the work at Imperial College London and HMI, Berlin is to examine how residual stresses and prior straining and subsequent relaxation at high temperature contribute to creep crack initiation and growth for steels relevant to power plant applications. Tensile residual stresses have been introduced in the weld by pre-compression and neutron diffraction measurements have been carried out before and after stress relaxation at 650 oC. Significant relaxation of the residual stresses has been observed, in agreement with earlier work on a stainless steel. Preliminary results suggest that the strains local to the crack drop by over 60% after 1000 h relaxation at 650 oC for the weld steel. The results have been compared with finite element studies of elastic-plastic pre-compression and stress relaxation due to creep.

Continuous Dynamic Recrystallization of AISI 430 Ferritic Stainless Steel by Hot Torsion Deformation

2005 ◽  
Vol 475-479 ◽  
pp. 145-148 ◽  
Author(s):  
Jae-Young An ◽  
Suk Min Han ◽  
Young Jae Kwon ◽  
Yeon Chul Yoo
Keyword(s):  
Stainless Steel ◽  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Ferritic Stainless Steel ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
High Angle ◽  
Continuous Dynamic Recrystallization ◽  
Continuous Dynamic ◽  
Aisi 430

The high temperature deformation behavior of AISI 430 ferritic stainless steel has been studied over a temperature range of 800 to 1000°C and strain rate of 0.05-5.0/sec. The evolution of flow stress and microstructures showed the characteristics of continuous dynamic recrystallization (CDRX). The flow stress curves gradually decreased with increasing strain over the peak stress until 500% of strain without any steady state shown in typical austenitic stainless steel. Sub-grains of low angle firstly formed along the original high angle grain boundary were propagated into the inside of original grain and transformed to high angle. The CDRX grain sizes of AISI 430 deformed at 1000 °C and 0.5/sec was about 30-35㎛.

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