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when austenite change into martensite, change in the temprature occurs(cooling). Due to this thermal stress devlop between the core and surface . Surface try to expand and core try to compress the size due to this a change in 'c' parameter take place. So a=b but not=c . this is called BCT stracture.
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What are some uses for martensite?
hardness of martensite is greater than bionite and fine pearlite.
Difference between lath martensite and plate martensite?
Lath martensite and plate martensite are two morphologies of martensite formed during the rapid cooling of austenitic steel. Lath martensite appears as thin, elongated plates or laths and is typically found in low-carbon steels, resulting in a more ductile microstructure. In contrast, plate martensite consists of thicker, broader plates and is generally found in high-carbon steels, leading to higher hardness and brittleness. The differences in their formation and structure influence the mechanical properties of the steel they comprise.
What is generator BCT?
BCT usually stands for bushing current transformer.
Is martensite formed when a steel is quenched?
Martensite transformation begins when austenite is cooled below a certain critical temperature, called the matrensite start temperature. As we go below the tmartensite start temperature, more and more martensite forms and complete transformation occurs only at a temperature called martensire finish temp. Formation of martensite require that the austenite phase must be cooled rapidly.
Why martensite is non equilibrium phase?
Martensite is considered a non-equilibrium phase because it forms rapidly during the quenching process, bypassing the slow diffusion-based transformations typical of equilibrium phases. Its formation involves a shear mechanism that occurs at low temperatures, resulting in a unique crystal structure that does not correspond to the equilibrium phase diagram. This rapid transformation does not allow for the atomic rearrangements required for equilibrium, leading to its metastable nature. Consequently, martensite possesses distinct mechanical properties compared to equilibrium phases like pearlite or bainite.
Why martensite is so hard and brittle?
For two reasons: 1. martensite is bct structure which prevent the movement of dislocations. 2. martensite has higher carbon concentraton.
What are some uses for martensite?
hardness of martensite is greater than bionite and fine pearlite.
Why pearlite makes steel harder?
Because Martensite transformation is almost instantaneous, the Martensite has the identical composition of the parent phase. Formation of Martensite involves a transformation from a body-centered cubic structure to body-centered tetragonal structure. The large increase in volume that results creates a highly stressed structure.
What structure forms in hypoeutectoid steel after full hardening?
Martensite
Difference between lath martensite and plate martensite?
Lath martensite and plate martensite are two morphologies of martensite formed during the rapid cooling of austenitic steel. Lath martensite appears as thin, elongated plates or laths and is typically found in low-carbon steels, resulting in a more ductile microstructure. In contrast, plate martensite consists of thicker, broader plates and is generally found in high-carbon steels, leading to higher hardness and brittleness. The differences in their formation and structure influence the mechanical properties of the steel they comprise.
Which is the harder among them Cementite or Martensite?
Martensite
What is lath martensite?
Low carbon content <0.6% results in lath structure as opposed to plate or needle structure for high carbon content >0.6%
What is matensite structure?
Martensite is a hard crystalline structure that forms in steel when it is rapidly cooled, often during quenching. It is characterized by a high strength and hardness due to its unique atomic arrangement. Martensite is not as ductile as other steel structures like pearlite, making it favorable for applications requiring hardness and strength.
What happens to austenite during quenching?
During quenching, austenite transforms into martensite through a rapid cooling process. This transformation involves the carbon atoms being trapped within the crystal lattice structure of the martensite, resulting in a hard and brittle microstructure.
When was BCT Commander created?
BCT Commander was created in 2002.
When did BCT Commander happen?
BCT Commander happened in 2002.
What is generator BCT?
BCT usually stands for bushing current transformer.
