ANALYSIS OF STRIP THERMAL CYCLE DIFFERENCES IN CONTINUOUS GALVANIZING LINES FOR STEADY STATE PROCESSING CONDITIONS

J. ETCHEVERRY; J. GAZZARRI; T. PÉREZ; M. A. VICENTE ALVAREZ; F. ACTIS; P. CANTARELLI; G. CERVELLINI; J. VON BERGEN

Houston

Congreso; Galvanizer01; 2001

AIST

In this work we present a detailed study of the differences in the thermal cycle to which different parts of the strip are subject in continuous galvanizing lines. These differences appear even in steady state processing conditions, due to variations in strip thickness, increased radiative and convective fluxes near the strip edges, and additional flux incoming through the strip edge. The study is threefold: on one hand, a careful analysis is made on the possible causes of non-uniformities in the thermal cycle, assuming steady state processing conditions. On the other hand, laboratory simulations performed using CINI´s Gleeble machine are carried out on a rephosphorized steel strip sample applying a) the standard thermal cycle; b) thermal cycles corresponding to ±10 % variations in thickness; and c) predicted thermal cycles for the edge of the strip. The mechanical properties and microstructures of the annealed material are then compared to those obtained for the same strip processed at Siderar CGL #1 (Haedo, Argentina), with results consistent with both on-line temperature readings and theoretical analysis.