Orientation distribution function analysis of the recrystallization texture in a boron-treated deep-drawing steel
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I.
INTRODUCTION
IT is well known that the plastic-strain ratio (?), which is a measure of the cup drawability of sheet steels, is greatly dependent upon crystallographic texture. ~-4 We have recently reported5 the recrystallization texture of a borontreated drawing quality steel, rolled 70 pct before annealing, to be qualitatively {111}Cl12), which is favorable from the point of view of drawability. This earlier report was based on (110) pole figure measurements. In the present paper we shall discuss the results now obtained using the orientation distribution function (ODF) analysis technique which has yielded more complete and quantitative information on the textural components present in our specimen. The present work comprises the first application of the ODF technique to boron-treated material. It should also be interesting, in a more general way, in view of the fact that in contrast to fcc-sheet materials the use of the ODF method has been rather limited for sheet steels (e.g., References 6 to 12). The present work is an example which will be valuable to distinguish between the general and the special features of the ODF's of such materials. Finally, the present example shall be used to demonstrate the possibility of a more quantitative characterization of the ODF of bcc metals by listing the volume fractions of the textural components as repeatedly done for fcc metals. ~3'~4
II.
EXPERIMENT AND RESULTS
A. Experimental The specimen used in this investigation was the one studied by us earliers for pole figure measurements, i.e., a commercial sheet of boron-treated steel of the composition (in wt pct) 0.06C, 0.40Mn, 0.027P, 0.031S, 0.040Si, and 0.004B, which, after the usual pretreatments,* was reduced *Steel making, casting, soaking, slabbing, preheating, hot rolling, pickling.
70 pct by reversed cold rolling to a final thickness of 1.26 mm and then recrystallization-annealed at 720 ~ for SANAK MISHRA is with Research and Development Centre for Iron and Steel, Steel Authority of India Ltd., Ranchi-834002, India. C. D~.RMANN and K. LUCKE are with Institut far Allgemeine Metallkunde and Metallphysik, Rheinisch-Westfalische Technische Hochschule, Kopernikusstrasse 14, D-5100 Aachen, West Germany. Manuscript submitted November 23, 1981. METALLURGICAL TRANSACTIONS A
24 hours. For ODF analysis, the method of incomplete pole figures ~5was used. Pole figure intensity data were obtained for (110), (200), and (112) reflections in the range 0 to 85 deg using the LOcke automated texture goniometer system ~6'j7 with Co Ka radiation. A random sample prepared from high purity iron-carbonyl powder was used for normalization. B. ODF Analysis In the present paper the analysis technique as developed by Roe 18'19and mainly by Bunge2~ was followed. Here the orientation of a crystallite is specified with respect to the specimen coordinate system by the three Eulerian angles 4,1, 0, and 4'2, and the orientation distribution function, f(g), representing the relative intensity of orientations, is computed in the form of a series
