Structural Changes in a 304-Type Austenitic Stainless Steel Processed by Multiple Hot Rolling

2011 ◽  
Vol 409 ◽  
pp. 730-735 ◽  
Author(s):  
Zhanna Yanushkevich ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev

The microstructure evolution and the dynamic processes of grain refinement in a 304-type austenitic stainless steel during multiple calibre hot rolling at temperatures of 700-1000°C were studied. The structural changes are characterized by the elongation of original grains towards the rolling axis and the development of new fine grains, the mean size of which decreases with decreasing the deformation temperature. During multiple rolling at 1000°C, the new grains resulted from the development of discontinuous dynamic recrystallization involving a bulging of frequently corrugated grain boundaries. On the other hand, the new grain boundaries leading to remarkable refinement of original microstructure were developed at temperatures below 800°C as a result of continuous strain-induced reactions.

2004 ◽  
Vol 467-470 ◽  
pp. 1163-1168 ◽  
Author(s):  
A. Dehghan-Manshadi ◽  
Hossein Beladi ◽  
Matthew R. Barnett ◽  
Peter D. Hodgson

A 304 austenitic stainless steel was deformed using hot torsion to study the evolution of dynamic recrystallization (DRX). The initial nucleation of dynamically recrystallization occurred by the bulging of pre-existing high angle grain boundaries at a strain much lower than the peak strain. At the peak stress, only a low fraction of the prior grain boundaries were covered with new DRX grains. Beyond the peak stress, new DRX grains formed layers near the initial DRX and a necklace structure was developed. Several different mechanisms appeared to be operative in the formation of new high angle boundaries and grains. The recrystallization behaviour after deformation showed a classic transition from strain dependent to strain independent softening. This occurred at a strain beyond the peak, where the fraction of dynamic recrystallization was only 50%.


2013 ◽  
Vol 753 ◽  
pp. 411-416 ◽  
Author(s):  
Andrey Belyakov ◽  
Marina Tikhonova ◽  
Zhanna Yanushkevich ◽  
Rustam Kaibyshev

The structural changes that are related to the new fine grain development in a chromium-nickel austenitic stainless steel subjected to warm working by means of multiple forging and multiple rolling were studied. The multiple warm working to a total strain of 2 at temperatures of 500-900C resulted in the development of submicrocrystalline structures with mean grain sizes of 300-850 nm, depending on processing conditions. The new fine grains resulted mainly from a kind of continuous reactions, which can be referred to as continuous dynamic recrystallization. Namely, the new grains resulted from a progressive evolution of strain-induced grain boundaries, the number and misorientation of which gradually increased during deformation. In contrast to hot working accompanied by discontinuous dynamic recrystallization, when the dynamic grain size can be expressed by a power law function of temperature compensated strain rate as D ~ Z-0.4, much weaker temperature/strain rate dependence of D ~ Z-0.1was obtained for the warm working.


1991 ◽  
Vol 13 (4) ◽  
pp. 227-241 ◽  
Author(s):  
C. D. Singh ◽  
V. Ramaswamy ◽  
C. Suryanarayana

The ODF analysis of the surface texture of the hot band of austenitic stainless steel reveals the presence of orientations of shear texture. These orientation elements are mainly distributed along two limited tubes of preferred orientations. The fibre of the first tube has its axis 〈110〉 ‖ RD and runs from {001} 〈110〉 to an orientation near {112}〈110〉 whereas the fibre of the second tube is inclined 30° from ND towards RD (i.e. 〈110〉 30° ND fibre) and stretches from {111}〈112〉 + 5° to the orientation near {112}〈110〉. The shear texture components are formed at the surface by shearing during hot rolling. Once they are formed, they get partly recrystallized by dynamic in situ recrystallization. On the other hand a duplex texture (i.e. retained copper type and recrystallization type) is present at the centre level of the hot band. The orientation elements of copper type (i.e. 〈110〉 60° ND fibre) are {011}〈112〉, ≈ {123}〈634〉 and {112}〈111〉 whereas the recrystallization texture components are dominated by cube {001}〈100〉 orientation and other RD rotated cubes through oriented nucleation during dynamic recrystallization.


Alloy Digest ◽  
2006 ◽  
Vol 55 (1) ◽  

Abstract CLC 18.10LN is an austenitic stainless steel with 18% Cr, 9.5% Ni, and 0.14% N to provide good corrosion resistance at strengths above the other low-carbon stainless steels. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, and joining. Filing Code: SS-950. Producer or source: Industeel USA, LLC.


2002 ◽  
Vol 41 (4) ◽  
pp. 487-495
Author(s):  
T. El-Bitar ◽  
A. Ismail ◽  
I. Rashid ◽  
M.R. El-Koussy

1913 ◽  
Vol 5 (3) ◽  
pp. 331-356 ◽  
Author(s):  
W. F Cooper ◽  
W. H Nuttall ◽  
G. A Freak

Results of our previous work were published in the Journ. of Agric. Sri., IV, 1911. There, also, a brief summary of the chief papers published on the subject of the fat globules was given, to which it is unnecessary to refer in detail here.When the work was first commenced in 1909, the problem before us was the consideration of the variation in the size of the fat globules, with relation to churning, as regards the different breeds of cattle. The breed was considered because it was usually supposed that this was one of the chief factors which influenced churning. The most definite result of our work was that it was shown that consideration must be given to the character of the milk, irrespective of the breed. This conclusion is quite contrary to that of other workers, but an examination of their figures shows, undoubtedly, that this is actually the case: the results given by Woll (Digestion Expts., Seventh Annual Report, Agric. Expt. Stat, Wisconsin, 1890, 238; also Agric. Sci., 1892, vi, 445) emphasise this point particularly. It is also shown by this year's work, as may be seen from Tables V–XI.The comparative size of the globules has been worked out very thoroughly by Gutzeit, who measured the mean volume of the globule. Other workers give their results as “relative sizes.” In our work we attempted to ascertain the distribution of the fat in the globules, and to this end the number of globules of each size was determined, and curves were drawn. The result of this, however, was negative. At that time we were considering the breeds of the cows from which the milks were obtained; had we considered them solely as milks of a certain mean size of globule, much more might have been achieved.An apparatus was devised to give an absolute figure for the churnability of any cream, but, until the effect of the other factors has been determined, it is impossible to interpret the results. Some experiments to ascertain the optimum temperature were described also.


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