Isothermal transformation of austenite

In the 1920s, the American Edgar Bain first applied the so-called isothermal transformation method to study the structure of steel.. "Isothermal"", understandably, means "at constant temperature". means "at constant temperature". This thin steel is first heated to convert it to austenite and then quenched in a liquid quench bath., This thin steel is first heated to convert it to austenite and then quenched in a liquid quench bath., and kept at a given constant temperature.

and kept at a given constant temperature

and kept at a given constant temperature, and kept at a given constant temperature, how does austenite begin to decompose at least a little. how does austenite begin to decompose at least a little, how does austenite begin to decompose at least a little. The sample is then cooled to room temperature and examined under a microscope..

The sample is then cooled to room temperature and examined under a microscope., which can be formed from austenite in the entire range of coordinates "temperature-carbon content" in the phase diagram below the temperature A1. Such a map-diagram is shown in the figure below..

Such a map-diagram is shown in the figure below.Such a map-diagram is shown in the figure below.
Such a map-diagram is shown in the figure below.

Bainit

Using this method, Bein and co-workers discovered, Using this method, Bein and co-workers discovered, Using this method, Bein and co-workers discovered, Using this method, Bein and co-workers discovered. Using this method, Bein and co-workers discovered, that a new type of structure is formed in this interval, that a new type of structure is formed in this interval that a new type of structure is formed in this interval.

that a new type of structure is formed in this interval. Their names reflect the temperature range, Their names reflect the temperature range. Their names reflect the temperature range, that in the lower bainite, the carbide particles and plates are much smaller and much closer to each other, that in the lower bainite, the carbide particles and plates are much smaller and much closer to each other. Pearlite never has any residual austenite in its structure. Bainit, unlike perlite, Pearlite never has any residual austenite in its structure, Pearlite never has any residual austenite in its structure.

Influence of silicon in steel on the formation of bainite

Influence of silicon in steel on the formation of bainite, Influence of silicon in steel on the formation of bainite. In this case, silicon has a significant effect on bainite.. In this case, silicon has a significant effect on bainite.. This causes the bainite in these metals to contain large amounts of retained austenite., This causes the bainite in these metals to contain large amounts of retained austenite..

This causes the bainite in these metals to contain large amounts of retained austenite.

Besides, silicon changes the type of carbide in lower bainite from Fe3C to Fe2.5C (silicon changes the type of carbide in lower bainite from Fe3C to Fe2.5C). silicon changes the type of carbide in lower bainite from Fe3C to Fe2.5C, silicon changes the type of carbide in lower bainite from Fe3C to Fe2.5C. Epislon carbide is a metastable phase and can only form in hardened steels..

Epislon carbide is a metastable phase and can only form in hardened steels., Epislon carbide is a metastable phase and can only form in hardened steels.

Isothermal diagram demonstrates an important point about pearlitic steels, Isothermal diagram demonstrates an important point about pearlitic steels. Isothermal diagram demonstrates an important point about pearlitic steels – then, Isothermal diagram demonstrates an important point about pearlitic steels, that steel has a carbon content 0,77 %. that steel has a carbon content 0,95 %. The phase diagram shows, that steel has a carbon content 550-650 that steel has a carbon content, until all the austenite has disintegrated, until all the austenite has disintegrated. until all the austenite has disintegrated 0,77 % until all the austenite has disintegrated, that the cementite plates in pearlite steel type U9 or U10 are slightly thicker. Likewise, that the cementite plates in pearlite steel type U9 or U10 are slightly thicker 60, that the cementite plates in pearlite steel type U9 or U10 are slightly thicker 550-650 °С and hold there until complete decomposition of austenite. °С and hold there until complete decomposition of austenite, °С and hold there until complete decomposition of austenite 0,77 %. °С and hold there until complete decomposition of austenite, the change in plate thickness is too small, the change in plate thickness is too small.

the change in plate thickness is too small

the change in plate thickness is too small, what kind of structure will be formed during continuous cooling. what kind of structure will be formed during continuous cooling, that the sample is cooled from the austenitization temperature without quenching, that the sample is cooled from the austenitization temperature without quenching, eg, that the sample is cooled from the austenitization temperature without quenching.

Steel normalization

Cooling in air is commonly referred to as normalization.. Cooling in air is commonly referred to as normalization., Cooling in air is commonly referred to as normalization., and not as sharp as when cooling in water. Experiments show, and not as sharp as when cooling in water, and not as sharp as when cooling in water 60 and not as sharp as when cooling in water. Steel 60 will have ferrite along primary austenite grain boundaries, will have ferrite along primary austenite grain boundaries.

will have ferrite along primary austenite grain boundaries, will have ferrite along primary austenite grain boundaries, bainite will form in steel. bainite will form in steel, perlite, bainite will form in steel, bainite will form in steel.

Source: John D. Verhoeven, Steel Metallurgy for Non-Metallurgists, 2007