mushroom_head
holey moley!
can someone plz explain to me how the percentage composition of carbon in steel can determine its properties? something to do with the more carbon, the more corrosive??
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corrosion: carbon in steel? (1 Viewer)
- Thread starter mushroom_head
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Xayma
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Yay for engineering studies finally helping for something.
The more carbon the more cementite (Fe<sub>3</sub>C) forms, this forms in phases with ferrite, to form pearlite up to .8% carbon, where all grains consist of pearlite.
Basically it will get harder, more brittle, loses a specific yield point (and goes to a progressive yield), less tensile, it also becomes denser (as carbon doesnt replace iron it takes in gaps between the structure.
In a steel under .8% (above that it gets slightly more complex) inside the grain the cementite acts as a cathode, whereas the ferrite phase is anodic, this corrodes and then the cementite due to its brittleness snaps off.
This also happens between the pearlite grains and ferrite grains.
Above .8% you form a cementite precipitate which generally stops corrosion around the grain boundries (areas of high stress). Then you get into the cast irons which is different again.
The more carbon the more cementite (Fe<sub>3</sub>C) forms, this forms in phases with ferrite, to form pearlite up to .8% carbon, where all grains consist of pearlite.
Basically it will get harder, more brittle, loses a specific yield point (and goes to a progressive yield), less tensile, it also becomes denser (as carbon doesnt replace iron it takes in gaps between the structure.
In a steel under .8% (above that it gets slightly more complex) inside the grain the cementite acts as a cathode, whereas the ferrite phase is anodic, this corrodes and then the cementite due to its brittleness snaps off.
This also happens between the pearlite grains and ferrite grains.
Above .8% you form a cementite precipitate which generally stops corrosion around the grain boundries (areas of high stress). Then you get into the cast irons which is different again.
mushroom_head
holey moley!
thanks! it was heaps of help!