1993 Fiscal Year Final Research Report Summary
On-Line Measurement of Steel r-Valur with Ultrasonic Method
| Project/Area Number |
03555020
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
材料力学
|
|---|
| Research Institution | OSAKA UNIVERSITY |
|---|
Principal Investigator |
FUKUOKA Hidekazu Faculty of Engr.Sci., Professor, 基礎工学部, 教授 (20029391)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FUJISAWA Kazuo Sumitomo Metal Indust., Senior Resarcher, システムエンジニアリング事業本部, 主任研究員
HIRAO Masahiko Faculty of Engr.Sci., Associate Professor, 基礎工学部, 助教授 (80112027)
|
|---|
| Project Period (FY) |
1991 – 1993
|
| Keywords | Nondestructive Measurement / Ultrasonic / Texture / Cold-Rolled Steel Sheets / r-Value / EMAT / On-Line Operation |
|---|
| Research Abstract |
Research has been made toward the on-line measurement of r-value for the steel sheets in the production line. The contactless technique relies on the measurement of ultrasonic velocities and relating them to the r-values. This is possible, because the anisotropy in velocities and the plastic anisotropy both arise from the texture which has developed during the hot rolling, the cold rolling, and finally annealing of the sheets.
Different principles, Lorentz force and magnetstriction, for the electromagnetic acoustic transducers (EMATs) were investigated for the contactless, quick measurement of phase velocities of the fundamental symmetric Lamb wave. Final decision was the magnetostrictive type, for which the electromagnets applied the bias field parallel to the sheet plane and the meanderline coil generated and detected the eddy current induced. This EMAT allowed the liftoff up to 5 mm with the sheet maximum 2 mm thick. Three pairs of them were placed along the three principal directions of the moving sheets. Averaged r-values were calculated using the average transit times and the regression curve. The measurement system containing these EMATs were tested at the end of the continuous annealing line of Sumitomo Metal Indust., resulting in the 0.1 error of r-values for maximum 400 m/min line speed despite the variation of the chemical composition, the thickness, etc. The measuring time was 20 msec per output. Corrections were necessary concerning the velocity dispersion, the liftoff, and the temperature change. It is concluded that the ultrasonic system developed can contribute to the quality assurance of the steel sheets in the real production environment.
|
