Steel research is the core research strength of this group. Several key basic concepts for enhancing the properties of the steel are very ardently explored by several scientists. This includes alloy modification, thermo-mechanical processing, and microstructure and structure engineering. State-of-the-art microstructure characterisation facilities such as; X-ray diffraction, Transmission electron microscope, scanning electron microscope, EPMA, Atom Force Microscope are available with this group. Customise devices such as Automated Ball indentation, annealing simulator etc. are being developed to conduct a desired experimental simulation. This group also closely interacts with industry and others to help solve their problems and failure analysis of in-service industrial components.
Research on Low-density high strength steels for their high performance is looked at by way of alloy and microstructure design. An effort is on to utilize a brittle intermetallic phase as a strengthening phase in high Al low-density steels. The objective is to develop duplex steel having microstructural constituents as ferrite, austenite and very fine precipitates of intermetallic (Kappa-carbide (FeMn)3AlC, B2-FeAl, D03-Fe3Al). Presence of intermetallic in steel deteriorates the mechanical properties, however, this can be overcome by controlled processing to obtain very fine, uniformly distributed intermetallic. A uniform dispersion of the intermetallic is expected to enhance the properties.
For applications involving the requirement of high wear resistance, concurrent enhancement in the hardness and toughness is mandatory. This is attempted by developing Bulk nano–pearlitic steel with interlamellar spacing in the range of 40 – 70nm in a continuous cooling process. The refined interlamellar spacing along-with fine pearlitic colony size imparts excellent hardness with adequate impact toughness to the steel.
Research efforts on ultra-high strength dual phase steel via microstructure engineering are underway. A core-shell type microstructure was created through controlled austenite decomposition, wherein core consists of hard martensite phase and fine ferrite surrounding the martensite as a shell. Such micro-structures found to exhibit high ductility at high strain rate tensile deformations. The ferrite channels at inter martensite grains retard the crack growth rate and prevent the crack from entering into adjacent martensite phase. This delays the onset of global level damage and results in necking and fracture. This crack growth delay mechanism seems to promote strain hardenability in the steel at ultra-high strength levels and enhances ductility.
High entropy alloys are multi-principle component systems with a microstructure consisting of random solid solution phase/s. The study on HEA at CSIR-NML aims at the development of HEAs for cryogenic applications and study of deformation behavior of the alloys. Recent studies revealed that certain HEAs are tougher when cold i.e. the toughness improved significantly when tested at -100 oC as compared to that of the room temperature toughness.
Effects of Inclusions on Pitting Corrosion on Line Pipe Steel, Metallurgical and fractographic examination of 304LN and its weld under cyclic and monotonic loading in air/water and air environment, On-site residual stress distribution profiling of hot rolled sheets at Hot strip mill, TSL Jamshedpur site, Failure Analysis of Superheater Tube of Boiler, Study of microstructure and texture evolution in low carbon formable steels, Development of process technology for third generation Advanced High Strength Steel (AHSS), Microstructural Characterization of Fusion Boundary of Ferrite-Nickel Based Alloy in Dissimilar Metal Weld, Effect of CAL parameters; temperature, time and cooling rates, on Ferrite+ martensite phase formation in DP steel, Optimisation of CAL annealing parameters for achieving r-bar greater than 2, Metallurgical Failure Investigation of Railway Components, Development of Quenched & Partitioned steel through Hot Strip Mill Route, Determination of stacking fault energy of cold rolled medium manganese steel by X-ray diffraction, Development of Electrical Steels