Non-destructive testing for characteristic parameters of rolled steel strip
The general aim was the correlation of characteristic technological values, i.e. for rolled strip products, with inspection values of non-destructive test techniques, in order to derive an in-field characterization of the material values. In a first step electromagnetic techniques have been used to investigate a wide range of different flat strip products (Al-killed, rimmed, hot rolled, cold rolled, batch annealed, skinpass rolled). Further work concentrated on the characterization of skinpass rolling for three thin sheet qualities with different yield strengths. The dynamic range of the inspection values documented in the previous tests could not be confirmed for Barkhausen-noise and incremental permeability inspection. Furthermore large differences were registered between straightened and unstraightened sheet-plates, caused by inhomogeneous residual stress distributions. In a second step the investigations concentrated on the characterization of the recrystallization process for three thin sheet qualities. Previous tests have documented a unique response of the coercivity derived from Barkhausen-noise profile curves with the state of recrystallization, including the state of grain size growth. The result was the development of prototype equipment, working with low magnetizing frequencies 1 Hz/5Hz.
Bibliographic Reference: EUR 11615 DE (1988) MF, 125 pp., ECU 8, blow-up copy ECU 16.25
Record Number: 198910371 / Last updated on: 1994-12-01
Original language: de
Available languages: de