What is bainitic transformation?
What is bainitic transformation?
The pearlite transformation involves the redistribution of carbon followed by a structure change, the martensite transformation involves the structure change alone, and, in contrast, the bainite transformation involves a structure change followed by the redistribution of carbon, which precipitates as a carbide.
How bainite is formed?
Bainite forms by the decomposition of austenite at a temperature which is above MS but below that at which fine pearlite forms. All bainite forms below the T0 temperature.
Which is harder bainite or martensite?
Tempered martensite and lower bainite are very similar in that they are both lath-like microstructures with small carbides within. Martensite has the potential to be stronger (higher hardness) which can mean better resistance to edge rolling or permanent bends in knives.
Why is bainite harder than pearlite?
The hardness of the reaction product also increases continuously with decreasing temperature, lower bainite being harder than upper bainite, which is harder than most fine pearlite.
What are the properties of bainite?
In the wrought ferrous industry, bainitic steels are known to exhibit high strength and hardness and also a high level of toughness. The aim of this research was to develop a bainitic microstructure in a PM steel that exhibits a high level of strength and toughness with acceptable ductility.
What is a bainite material?
A fine non-lamellar structure, bainite commonly consists of cementite and dislocation-rich ferrite. The large density of dislocations in the ferrite present in bainite, and the fine size of the bainite platelets, makes this ferrite harder than it normally would be.
What is bainite and its properties?
The general definition of bainite is that the microstructure consists of a non-lamellar mixture of ferrite and carbides. More specifically, upper bainite consists of lath or plate shaped ferrite arranged in packets separated by layers of cementite particles (Figure 1).
Why is bainite tougher than pearlite?
The large density of dislocations in the ferrite present in bainite, and the fine size of the bainite platelets, makes this ferrite harder than it normally would be. The temperature range for transformation of austenite to bainite (125–550 °C) is between those for pearlite and martensite.
