Microstructures and Charpy impact properties have been examined in two microalloyed steels following heat treatments to simulate weld heat affected zone (HAZ) structures over a range of heat input conditions, characterised by the cooling time from 800 to 500 !C (Dt8/5). The base materials were low carbon structural steel plates microalloyed with vanadium and nitrogen (V–N) and niobium (Nb), res...

Bainite has been obtained by heat treatment at temperatures as low as 125°C in a high carbon, high silicon steel. This has had the effect of greatly re® ning the microstructure, which is found to have a strength in excess of 2.5 GPa together with an ability to ̄ ow plastically before fracture. Such properties have never before been achieved with bainite. In this paper metallographic details are ...

Recent work has shown that bainitic ferrite plates produced by transformation at low temperatures can be as thin as 20 nm with a hardness in excess of 650 HV30, tensile strengthy2.3 GPa and toughnessy30 MPa m. Because these properties rely on the fine scale of the microstructure, a study has been carried out in relation to the tempering resistance of steel over the temperature range 350 – 750uC...

In industry, the cost of production is an important factor and it is preferred to use conventional and low cost procedures for producing the parts. Heat treatment cycles and alloying additions are the key factors affecting the microstructure and mechanical properties of the cast steels. In this study an attempt was made to evaluate the influence of minor Mo addition on the microstructure and me...

Neural network predictions suggested that strength of a high strength steel weld metal with 7 wt. % nickel and 0.5 wt. % manganese could be increased significantly at moderate expense to impact toughness by additions of carbon. Based on this, three experimental weld metals were produced with carbon levels between 0.03 and 0.11 wt. %. Mechanical test results were in agreement with predictions. W...

In-situ time-resolved X-ray diffraction technique with synchrotron radiation was used to track austenite decomposition in steels. Measurements from a Fe-C-Si-Mn steel indicate two lattice parameters in the austenite, possibly due to the development of carbon-rich and carbon-poor austenite prior to transformation. The lattice parameter became uniform with the progress of transformation and the f...