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Title: Microstructure-mechanical property relationships in vanadium bearing high strength low alloy (HSLA) strip steels
Author: Khoo, C. A.
Awarding Body: University of Wales Swansea
Current Institution: Swansea University
Date of Award: 2006
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High Strength Low Alloy (HSLA) strip steels have extensive applications in the automotive industry, due to their excellent combination of strength, toughness and suitable formability characteristics. The purpose of the present study is to study the control of austenite grain size via second phase particle additions, based on titanium and combine titanium-vanadium microalloy additions. Processing of HSLA strips steels aims to produce a fine austenite grain size resulting in the subsequent formation of a fine primarily ferritic product. Two experimental titanium and titanium-vanadium HSLA grades were studied as part of this comparative study. The present study confirmed that vanadium carbide precipitates successfully control the austenite grain size at low austenitisation temperatures <1000ºC by effectively pinning the austenite grain boundaries. However, at higher austenitisation temperatures >1000ºC rapid dissolution of vanadium carbides particles does occur and the importance of titanium nitride formation in controlling the austenite grain size in both experimental grades, becomes evident. The present study also identified the critical parameters in processing of the two novel HSLA grades studied as for the finishing hot rolling temperature, cooling rate between finishing and coiling temperature and coiling temperature concerned. Based on this study a recommendation for an optimised steel processing route in titanium-vanadium HSLA grade is made facilitating the production of enhanced quality hot rolled strip steel products.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available