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The current work demonstrates the microstructural evolution and mechanical property evaluation of a newly designed steel composition after hot rolling in laboratory-scale rolling mill, followed by continuous cooling. The steel thus developed has typically about 80% carbide-free bainite; about 20% retained austenite and can deliver ~1400 MPa ultimate tensile strength along with more than 20% total elongation. The presence of ultra-fine bainite plates (~100-130 nm thick) with high dislocation density was thought to be responsible for ultra-high strength. Excellent ductility at such strength level could be due to the presence of sufficient amount of retained austenite (~20%) thermally stable at room temperature but starts transforming to martensite during deformation exhibiting transformation-induced plasticity effect. [ABSTRACT FROM AUTHOR]

The current work demonstrates the microstructural evolution and mechanical property evaluation of a newly designed steel composition after hot rolling in laboratory-scale rolling mill, followed by continuous cooling. The steel thus developed has typically about 80% carbide-free bainite; about 20% retained austenite and can deliver ∼1400 MPa ultimate tensile strength along with more than 20% total elongation. The presence of ultra-fine bainite plates ~100-130 nm thick) with high dislocation density was thought to be responsible for ultra-high strength. Excellent ductility at such strength level could be due to the presence of sufficient amount of retained austenite (~20%) thermally stable at room temperature but starts transforming to martensite during deformation exhibiting transformation-induced plasticity effect. [ABSTRACT FROM AUTHOR]

Two new low alloyed steels were developed with different fracture toughness values but at similar level of hardness with same composition and microstructural phase. The steels were subjected to impact-abrasion wear test. This work examines specifically the additional role of toughness during impact-abrasion wear, using a newly developed high toughness steel. Microstructural characterisation of the damaged samples revealed that better toughness helps resist both impact and abrasion damage.