COMPARATIVE INVESTIGATIONS OF INTERFACIAL HEAT-TRANSFER BEHAVIOR DURING HOT-FORGING AND ROLLING OF STEEL WITH OXIDE SCALE FORMATION

In this paper, the results of hot axisymmetric forging and flat rollin g experiments using plain carbon steel with oxide formation conducted under nearly identical conditions of initial temperature, specimen thi ckness and surface quality, and deformation speed and reduction are pr esented. Temperature measurements and computations indicate that, unde r the approximately identical deformation conditions, the interfacial heat transfer coefficients (IHTCs) from hot rolling are substantially higher than those from hot forging. The thermal and physical mechanism s governing these differences are analysed in terms of oxide scale def ormation mode, metal flow pattern and contact status. (C) 1998 Elsevie r Science S.A. All rights reserved.