Cementite is harder than austenite because it is a compound of iron and carbon with a well-ordered crystal structure, whereas austenite is a solid solution of iron and carbon with a disordered structure. The ordered structure of cementite provides greater resistance to deformation and makes it harder.
The lowest temperature at which austenite transforms into ferrite and cementite. Steel with 0.77 percent carbon transforms at this temperature. Learn more abouteutectoid temperaturein the classHeat Treatment of Steel 230below.
Annealing is a process in which a material is treated to re-crystallise and get into its stable form, i.e to align its axis to there characteristic directions. here sample is ist heated to a certain temperature,maintaines at that temperature for a specified time and then allowed to cool down to room temperature. The process involves recrystallization to form new, strain-free grains, and then grain growth of grains in the metal (or material).
Cementite has a chemical formula Fe3C, which means it contains 25.9% carbon by weight.
To work harder than your hardest involves you pushing yourself to the limit, working harder than you ever have before.
Why is quartz harder steel
ledeburite
Martensite
Well, basically, pearlite is the eutectic composition of steel, with an overall composition of 0.8% carbon. It is known to consist of two phases, namely: Ferrite (Fe), the room temperature of iron and Cementite(Fe3C). Therefore, the difference between pearlite and cementite is that pearlite is a composition of steel, and cementite is a composition of Pearlite. So cementite is part of pearlite.
probably because of different thermal expansion of carbide matrix phase with pearlite or austenite disperses, at cooling a high dislocation density apears in phases, especially deformable one, and this high dislocation density is responsible for higher hardness
The lowest temperature at which austenite transforms into ferrite and cementite. Steel with 0.77 percent carbon transforms at this temperature. Learn more abouteutectoid temperaturein the classHeat Treatment of Steel 230below.
The are three types of cementite which form in different ways. There's the primary that forms from crystalization from the molten iron above 4.3%C and below 6.7%C (line CD in Fe-Fe3C diagram), secondary cementite which forms from precipitation from austenite at the right side of the eutectoid point. And there's the tertiary cementite which forms as precipitation from ferrite alpha because of the falling solubility of carbon in ferrite as temperature goes down.
Pearlite is a microstructure formed in steel with a specific carbon content, characterized by alternating layers of ferrite and cementite, while ledeburite is a less common microstructure formed at extremely high carbon levels, primarily composed of cementite and austenite, and is brittle in nature.
The various phases that exist on the Fe-Fe3C diagram are austenite, ferrite, cementite (Fe3C), and a mixture of ferrite and cementite known as pearlite. These phases form at different temperatures and carbon concentrations, and their distribution determines the properties of the steel.
Eutectic point is where a liquid eutectic composition cools sufficiently to solidify.Eutectoid point is where, within a solid, the material cools enough to undergo a phase transformation. e.g. austenite to cementite a
The eutectoid point of plain carbon steel is approximately 0.76% carbon content. At this composition, the steel undergoes a phase transformation from austenite to a mixture of ferrite and cementite during cooling, resulting in the formation of pearlite microstructure.
Pearlite is a layered structure of ferrite and cementite formed by the eutectoid reaction in steel, while ferrite is a pure form of iron in its BCC crystal structure. Ferrite is soft and ductile, while pearlite is harder due to the presence of cementite.
It heavily depends on which type of stainless steel you're referring to and what your definition of strong is. High carbon and perhaps plain carbon steels would be harder then austenite and ferritic stainless, but martensitic stainless would be harder then plain/high carbon. Austenite and ferritic stainless would be tougher and austenite would have have highest degree of corrosion resistance. I consider a steel to be "strong" if it has a balance of hardness and toughness in which case,I would say martensitic stainless steels.