Vanadium - Transforming Possibilities

The Mechanical Properties and Microstructure of Vanadium Molybdenum Steel Plates and Strip for X80 and X90 Spiral Pipes

Abstract:

Vanadium has been employed with molybdenum in a number of HSLA steels used for pipe lines, pipeline fittings and other structures but in most of these steels the molybdenum has been added to produce a microstructure containing transformation products, particularly acicular ferrite, and the vanadium has been added to increase the strength of the polygonal ferrite. Such structures can give rise to a continuous stress strain relastionship in the tensile test which enables the bauchinger effect to be overcome when producing pipes. Little attention has been paid to the effect of smaller additions of molybdenum to vanadium steels having predominantly a polygonal ferrite pearlite structure which can be used for both pipelines and other structures. This paper summarises the various steel types where vanadium is used with molybdenum and includes the results of recent work on polygonal ferrite pearlite steels containing small additions of molybdenum (<0.1%).