Measurement of recovery and recrystallisation in interstitial free steels using electromagnetic sensors

Hall, Russell (2018). Measurement of recovery and recrystallisation in interstitial free steels using electromagnetic sensors. University of Birmingham. Ph.D.

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Abstract

Interstitial free (IF) steel is used extensively throughout applications in the automotive, packaging and furniture industries due to its excellent formability and ductility. The manufacturing process ensures excellent material properties for subsequent forming processes are developed through the formation of a fine equi-axed grain structure and crystallographic texture.

The annealing process improves the formability of the cold rolled IF sheet, whilst also reducing strength through the recovery and recrystallisation process. After the cold rolling process the grain structure is heavily deformed. During the recovery process the dislocation density is reduced through annihilation and redistribution of dislocations to form sub grains. During the recrystallisation process new grains nucleate and grow into new, strain free, grains.

Magnetic properties of ferromagnetic material are known to be affected by microstructural phenomena such as dislocation density, grain boundaries, grain size and texture. It is therefore possible to monitor the recovery and recrystallisation processes using sensors that are responsive to changes in magnetic properties. The purpose of the research completed was to establish whether it would be possible to use electromagnetic (EM) sensors to monitor recovery and recrystallisation processes in-situ during heat treatment, such that EM sensors could then be deployed in a continuous annealing line.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):