Propagation and termination of an internal crack in continuously cast austenitic stainless steel analyzed by ∑ values and the Schmid factor

2017 ◽  
Vol 31 (2) ◽  
pp. 65-71 ◽  
Author(s):  
Youichi Saito ◽  
Shun-Ichiro Tanaka
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Internal Crack ◽  
Schmid Factor ◽  
Continuously Cast

Misorientation Measurement of Individual Grains in Fatigue of Polycrystalline Alloys by Diffraction Contrast Tomography Using Ultrabright Synchrotron Radiation

2016 ◽  
Vol 879 ◽  
pp. 1355-1360 ◽  
Author(s):  
Yoshikazu Nakai ◽  
Daiki Shiozawa ◽  
Ryota Nakao ◽  
Naoya Asakawa ◽  
Shoichi Kikuchi
Keyword(s):  
Stainless Steel ◽  
Synchrotron Radiation ◽  
Austenitic Stainless Steel ◽  
Pure Iron ◽  
Polycrystalline Materials ◽  
Mapping Technique ◽  
Diffraction Contrast ◽  
Commercially Pure ◽  
Schmid Factor ◽  
Individual Grains

A three dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8, which is the brightest synchrotron radiation facility in Japan. The developed technique was applied to a commercially pure iron and austenitic stainless steel. The shape and location of grains could be determined by DCT using the apparatus in a beam line of SPring-8. To evaluate the dislocation structure in fatigue, the total misorientation of individual grains was measured by DCT. The average value of the total misorientation over one sample was increased with the number of cycles. In a grain, the change of the total misorientation was largest for primary slip plane. For austenitic stainless steel (fcc), the change of the total misorientation in fatigue was larger for planes with larger Schmid factor, while it was not depended on the Schmid factor for commercially pure iron (bcc). This different behavior must come from planer slip in fcc structure and wavy slip in bcc structure.

scholarly journals The Effects of Electromagnetic Stirring on Cast Structure of Continuously Cast Austenitic Stainless Steel Slabs

1983 ◽  
Vol 69 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Hidemaro TAKEUCHI ◽  
Shogo MATSUMURA ◽  
Yasunobu IKEHARA ◽  
Tadaaki KOMANO ◽  
Takashi YANAI
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Electromagnetic Stirring ◽  
Cast Structure ◽  
Continuously Cast ◽  
Steel Slabs

Effect of Geometry and Distribution of Inclusions on the VHCF Properties of a Metastable Austenitic Stainless Steel

2014 ◽  
Vol 891-892 ◽  
pp. 440-445 ◽  
Author(s):  
Andrei Grigorescu ◽  
Philipp Malte Hilgendorff ◽  
Martina Zimmermann ◽  
Claus Peter Fritzen ◽  
Hans Jürgen Christ
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Crack Initiation ◽  
Rolling Direction ◽  
Microstructural Characterization ◽  
Martensite Phase ◽  
Internal Crack ◽  
Martensite Content ◽  
Metastable Austenitic Stainless Steel ◽  
Number Of Cycles

The effect of inclusions on the VHCF properties of a metastable austenitic stainless steel in undeformed and predeformed condition was studied. The material contains an inhomogeneous distribution of elongated oxide inclusions. TEM investigations of foils extracted by means of FIB technique show that the stress concentration at the inclusions is compensated by plastic deformation in the austenite phase preventing internal crack initiation in the VHCF regime for the non-predeformed, i.e., almost martensite-free condition. The effect of the spatial distribution and geometry of the inclusions on the VHCF strength was systematically investigated for the predeformed condition. Samples were monotonically predeformed at -80°C resulting in a martensite content of about 60% and then fatigued in high frequency testing machines. Since mechanical components are in practice subjected to complex cyclic loading situations, samples were tested both parallel and transversal to the rolling direction, in order to cover a broad field of applications. The higher notch sensitivity of the martensite phase leads to internal crack initiation from inclusions supported by the formation of a fine granular area (FGA). The change in testing direction perpendicular to the rolling direction reduces the number of cycles to failure due to the increased stress intensity factor at inclusions which leads to internal crack initiation without the formation of a fine granular area. These findings are discussed on the basis of a detailed microstructural characterization of the material focusing on the effect of martensite content, the inclusion morphology with respect to the rolling direction and the load axis applied

Some aspects of the defect structure in an austenitic stainless steel

1978 ◽  
Vol 36 (1) ◽  
pp. 314-315
Author(s):  
R. Gonzalez ◽  
L. Bru
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cellular Structures ◽  
Total Strain Amplitude ◽  
Total Deformation ◽  
Density Of Dislocations ◽  
Planar Arrays ◽  
Stacking Fault Tetrahedra ◽  
Distribution Of Dislocations ◽  
Very High

The analysis of stacking fault tetrahedra (SFT) in fatigued metals (1,2) is somewhat complicated, due partly to their relatively low density, but principally to the presence of a very high density of dislocations which hides them. In order to overcome this second difficulty, we have used in this work an austenitic stainless steel that deforms in a planar mode and, as expected, examination of the substructure revealed planar arrays of dislocation dipoles rather than the cellular structures which appear both in single and polycrystals of cyclically deformed copper and silver. This more uniform distribution of dislocations allows a better identification of the SFT.The samples were fatigue deformed at the constant total strain amplitude Δε = 0.025 for 5 cycles at three temperatures: 85, 293 and 773 K. One of the samples was tensile strained with a total deformation of 3.5%.

A TEM microscopical investigation of the magnetic domain structure of a metastable austenitic stainless steel

1994 ◽  
Vol 52 ◽  
pp. 696-697
Author(s):  
G. Fourlaris ◽  
T. Gladman
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cold Rolling ◽  
Solution Treatment ◽  
Magnetic Domain ◽  
High Strength ◽  
Medium Carbon Steel ◽  
Magnetic Characteristics ◽  
Metastable Austenitic Stainless Steel

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.

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