The decomposition of austenite to ferrite or cementite begins at the equilibrium phase boundary of austenite/ (ferrite austenite) or austenite/(cementite austenite) in binary Fe–C phase diagram. The temperature values on the phase boundaries of austenite/(ferrite austenite) and austenite/(cementite austenite) at a certain carbon content are called Ae3 and Acm temperatures of the steel, respecti...

To apply the duplex type low-carbon medium-manganese steel to hot/warm-forging and -stamping products, influence of cooling process routes immediately after intercritical annealing such as air-cooling (AC) isothermal transformation (IT) processes on impact toughness 0.2%C-1.5%Si-5%Mn (in mass %) medium-Mn (D-MMn) was investigated. Moreover microstructural tensile properties were also The AC inc...

The microstructural evolution of Fe–0.2C–5Mn steel during intercritical annealing with holding time for up to 144 hours was examined by TEM and STEM. It was demonstrated by TEM that the martensite lath structure gradually transformed into a lamellar ferrite and austenite duplex structure. The partitioning of manganese from ferrite to austenite was found by STEM. Typical Kurdjumov-Sachs orientat...

Breaking the strength-ductility paradox of very-low (≤0.05 wt.%)-C medium (3–12 wt.%)-Mn steels (MMnS) has been a hard-wired topic, since in these multi-step heat treatments are usually required to obtain austenite for improved ductility and precipitates higher strength. In this study, compact two-step treatment comprising short (2 min) annealing tempering was developed investigate synergetic e...

This study investigated the microstructures of pearlite and martensite transformed from ultrafine-grained austenite in 0.45C steel and Vadded 0.45C steel. The mean prior austenite grain sizes were refined to be 4.5 μm in the 0.45C specimen and 2.4 μm in the V-added 0.45C specimen through cyclic heat treatment of austenitizing and water quenching, i.e., repetition of martensite § austenite trans...

The effect of different austenite grain size and different cooling rates on the austenite to ferrite transformation temperature and different ferrite morphologies in one Nb-microalloyed (HSLA) steel has been investigated. Three different austenite grain sizes were selected and cooled at two different cooling rates for obtaining austenite to ferrite transformation temperature. Moreover, samples ...

The effect of long-term ageing (1000, 2000, and 3000 h) at 475 °C on mechanical properties, microstructure, substructure CUSTOM 465® maraging stainless steel was studied. additional precipitation nanometric particles ?-Ni3Ti phase in partly recovered lath martensite decomposition the BCC solid solution accompanied by formation Cr-rich ?’particles were identified. fraction reverted austenite fin...