| Abstract |
| A study has been made of the grain growth in IF steel during strain annealing. A 92.3% cold rolled and annealed IF steel sheet was temper rolled by 0.4% and subsequently annealed at 670, 750 and 850℃ for various time periods in 25%H2 + 75%N2. The grains occasionally started to grow abnormally near the surface and grew into the center during strain annealing. The pole figure and EBSD measurements showed that the abnormally grown grains did not have any orientation relation with the primary recrystallization texture before temper rolling. Thus, the major coarsening mechanism was regarded to be the strain induced grain boundary migration rather than grain boundary characteristics. The permeability increased initially and then decreased along with the increased of grain size, therefore there existed an optimum grain size showing maximum value of permeability. The maximum permeability was measured up to be 13,000, then optimum grain size is 83 μm at 850℃ for 30 min. |
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| Key Words |
| strain annealing, grain coarsening, permeability, SIGM, EBSD |
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