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Direct charging of thin slabs of a cold formable HSLA steel
Author(s) -
Bruns Hartmut,
Kaspar Radko
Publication year - 1997
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199701781
Subject(s) - materials science , casting , metallurgy , slab , ultimate tensile strength , continuous casting , deformation (meteorology) , microstructure , composite material , austenite , alloy , structural engineering , engineering
In the concept of direct charging linking continuous casting with rolling of thin slabs, some differences in the design of process parameters are necessary. By example of a commercial low carbon NbTi‐microalloyed steel, laboratory tests have been carried out by using a thin‐slab continuous casting simulator on‐line with the hot deformation simulator Wumsi. The influence of the temperature of intermediate holding (between casting and rolling), total strain ε Σ , finishing temperature and cooling rate after finishing on the microstructure and mechanical properties was investigated on rolling schedules with or without roughing prior to finishing. Conventional cold charging (with reheating of thicker slabs) was simulated as a comparison to this. Whereas the static properties (tensile test) were less influenced by ε Σ and by the design of rolling schedule (with or without roughing), the properties measured by the low temperature impact test (at ‐30°C) were more sensitive. By the optimizing process parameters of direct charging (finishing at temperatures of lower austenite, employing accelerated cooling after rolling) mechanical properties superior to those of cold charging (despite of largely reduced ε Σ ) are attainable.