Calculating Model of Mean Strain in Rod Rolling Process

An experimental study of the mean effective strain in rod (or bar) rolling process

“…With the elastic and shear strain components neglected, the incremental plastic deformation along each principal axis can be assumed to be proportional [9], i.e., del :de2:de3 = el :e2:e3 (I)…”

“…In recent times, Lee [9] proposed an analytical model anchored in a fundamental theory of plasticity that calculates the pass-by-pass mean effective strain associated with the oval-round (or round-oval) sequence most commonly employed in present continuous bar (or rod) mills. Using the area strain model [7] and the analytical model [9], Lee et aL [10] presented a series of numerical simulations, focusing on the effect of the calculating method of the pass-by-pass strain on the recrystallization behavior and evolution of AGS (austenite grain size) during bar rolling, by incorporating the recrystallization and AGS evolution model being widely used in hot plate (or strip) rolling.…”

“…Using the area strain model [7] and the analytical model [9], Lee et aL [10] presented a series of numerical simulations, focusing on the effect of the calculating method of the pass-by-pass strain on the recrystallization behavior and evolution of AGS (austenite grain size) during bar rolling, by incorporating the recrystallization and AGS evolution model being widely used in hot plate (or strip) rolling. The problem, however, of the validity of the analytical model [9] still remains; this is the basis of this study.…”

“…The pass schedule for bar rolling has been designed using the analytical model [9] such that the material (workpiece) during rolling experiences the same amount of mean effective strain at each pass for plate rolling and bar rolling. The purpose of warm rolling (650~ is to make the material free from the phase transformation during rolling and/or inter-pass time.…”

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This paper presents an experimental study that investigates the validity of the analytical model [9] for predicting the mean effective strains associated with bar (or rod) rolling. Designed for this purpose were plate and bar rolling experiments which consist of a four-pass groove (oval and round) rolling sequences, which have material at each pass that experience the same amount of mean effective strain.

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