Holy cow this man has cleared my doubts in just opening 4 minutes.. god our teachers are so bad any poorly information understood that they make us confuse whole life ... Thanks to you sir. Ur life saver
This is a clear explaination that puts the diagram in context, which for me personally makes it far more valuable tham learning it by heart 'just because'. This video also contains a rare moment of a German person displaying emotion around 15:24 :)
Professor Bonnet, thanks for the efforts of making us understand Werkstoffkunde in English and please request your fellow colleagues also to make videos in English for us Southasian student who despite having english as second language, decided to move to Germany to study engineering in German language and leaving english speaking countries like Canada US out of option because of the high tution fees. Nur ein Jahr dsh oder studienkolleg reicht nicht aus, um fließend deutsch zu sprechen und zu verstehen. und wenn der Professor seinen Vortrag in seiner Muttersprache hält, ist es ziemlich schwer, alles zu verstehen, so dass RU-vid unsere einzige Alternative ist. Also mach bitte mehr Videos in Englisch, wenn möglich auch mit deutschen wissenschaftlichen Begriffen. zurzeit: Ich verstehe nur Bahnhof und Mathe : )
When the iron/carbon is in a certain phase at high temperature, does it retain the physical characteristics of tgat phase when cooled to room temperature? Perhaps cooled rapidly? Otgerwise can't see application of these characteristics using a molten metal...
Great video, Professor, tnx a lot. Could you please clarify a bit one subtle point: up to this moment I was absolutely sure (and this fact is underpinned by my university course book) that alpha iron is the allotrope formed by iron, and ferrite is the solid solution of carbon in alpha iron? Did I miss something crucial?
I believe you are getting confused with the terms alpha iron and alpha ferrite. alpha iron is the allotrope whereas alpha ferrite is the solid solution of carbon in alpha iron
Just to make things crystal clear: alpha iron is the PURE element with bcc lattice, while alpha ferrite is the solid solution of atoms of carbon in the lattice of bcc iron (i.e. this is an alloy).
Like in any other phase diagram with decreasing solubility in the solid state, the solubility decreases below the eutectical with decreasing temperature.
Professor,I have a question if it's possible. maximum solubility of carbon in FCC iron is 2% but steel is produced below 1.4% carbon and cast iron is produced between 3-4.5% carbon. Why?
At room temperature most steel are BCC and have no solubility for Carbon, so that they contain cementite. Some properties improve with increasing cementite content while others get worse. Therefore most kinds of steel don't even contain more than 0,8% carbon. Cast iron shows best properties close to the eutectic concentration and slightly under. So in short: not all carbon concentrations make a lot of sense for most applications.
Allthough the general ledeburite microstructure will be the same at room temperature the ledeburite transitions into perlite and cementite below the PSK line
@@WeltderWerkstoffe Give the reason(s) for the following statements 1- Grey cast iron used in construction of heavy duty machines 2-White cast iron very hard and brittle The mechanical properties of ductile iron and malleable iron approximately the same Ductile iron with pearlite matrix stronger than ductile iron with ferrite matrix. Compact graphite irons (CGIs) is used for manufacturing exhaust manifolds. Chapter Five Cast Iron.pdf
Moot point but it ain’t pronounced “I-Ron”. Makes it impossible to watch. Let me know when the new version with the right UK English ( not the Yank crap) pronunciation is out.
