Effect of thermomechanical processing on the microstructure and propertiesof a low carbon copper bearing steel

A boron treated copper bearing HSLA steel containing austenite formers like manganese and nickel, somewhat lower in amount than that in HSLA 100 varie ty of steel is chosen for the study. The role of thermomechanical processin g on the microstructure and mechanical properties of the above steel has be en investigated. Differential scanning calorimetric study is carried out fo r understanding the precipitation behaviour of copper in HSLA steel under t he influence of boron. The microstructure of the experimental steel is foun d to consist of laths of martensites and bainite. MA constituents of ribbon like morphology are observed at the lath boundaries. Higher strength prope rties of the steel are attributed to the presence of finely distributed pre cipitates of copper and microalloy carbides.