Welcome to my youtube channel mechanical magic mechanical learning tutorials. So today I am talking about how to draw iron carbon diagram in a simple way. So before starting to draw the iron carbon diagram so some of the important reactions or important point that will be carried on to the iron carbon diagram so let us start with the some of the important point yes you can see over here peritactic reactions.
So generally the peritactic reaction it will be take place at the higher temperatures. So around 1493 degree centigrade and the low amount of carbon is present into the materials. So 0.18 percentage of carbon. So peritactic reactions in that case liquid plus delta form of the iron that will be converting into the gamma austenite which is a soft face and that will be the hundred percent solid materials of steel so generally that will be formed at the above 723 degree centigrade Now second reaction eutectoid reaction so after the peritectic reaction it forms the gamma austenite so that gamma austenite by the cooling at around 723 degree centigrade and the 0.8 percentage of carbon so that will be converting into alpha ferrite plus Fe3C that means cementite.
Or you can say that will be forms a proper mixture of alpha ferrite plus cementite and it will be called as a pearlite. So pearlite just you can find at the 0.8 percentage of carbon. Third reaction. So that will be the eutectic reaction so in that case liquid phase of 4.3% of carbon at 1147 degree centigrade that will be converting into gamma austenite plus Fe3C means cementite. If it will be making a proper mixture of gamma austenite plus cementite so that will be called as a ladeburite.
So here it will be the three main equations or you can say reactions peritectic reactions so generally liquid plus delta iron at 0.18 percentage of carbon and 1493 degree centigrade converting into gamma austenite that gamma austenite it will be converting in the case of eutectoid reactions so gamma austenite at 723 degree centigrade and 0.8 percentage of carbon you it will be converting into pearlitic structure. So pearlite is nothing but alpha ferrite plus cementite. And the third reaction and that will be eutectic reaction.
So in that case liquid phase it will be converting at 1147 degree centigrade and 4.3% of carbon in the form of gamma austenite plus cementite or you can say leadaburide. Now starting with the... draw the iron carbon diagram. So I put onto the x axis and that will be the weight percentage of carbon and y axis that will be the temperature in the form of degree centigrade.
So starting with the weight percentage of carbon so here you can see that the temperature is about 0.0008% of carbon Next point 0.18% of carbon 0.8% of carbon 1 two three and important point four point three and final six point six seven so now on to the y-axis one five 39 degree centigrade So on weight percentage of carbon this much point is enough and from the y axis or you can say the temperature that much point is enough. And one more point I will added over here that will be. 1147 degree centigrade. Now starting with the peritectic reaction or you can say 0.18% of carbon and 1493 degree centigrade.
So here it will be the one point that will be representing as a peritectic point. So just I want to draw one horizontal line like this so this line is only up to the 0.5% here 0.18% and from this side 0.1% right and just you can make one triangle from this side So that will be representing as a peritectic point. Right Now I am taking the second reaction and that will be the eutectoid reactions.
So generally eutectoid reaction it will be take place at 0.8% carbon and 723 degree centigrade. So 0.8 and 723. So once again one horizontal line. So here it will be not touching the temperature line.
So here it will be the point of 0.025% of carbon and this point it will be representing as a eutectoid point. So making one vertical line and once again making a triangle from solubility of alpha ferrite. Now the third point and that will be eutectoid reaction point so generally that will be 4.3% of carbon and 1147 degree centigrade. So around this so that will be representing as a eutectoid point draw one horizontal line.
And from this side up to the 2% carbon. So that would be the category of steel. Right?
Now I would like to join these all lines like this. and put over here that will be your eutectic point. Now putting the phases of iron iron carbon diagram and that will be starting from the top side. So that will be called as a liquidus line. So here 100% liquid Now once again starting with the peritectic reaction so in that case liquid plus delta iron that will be converting into gamma austenite.
So here it will be the point of the peritectic reaction so just so liquid plus delta that will be converting into gamma austenite. So now important point from upper side here it will be only formation of delta and at lower temperature range it forms alpha ferrite. Right.
So here gamma austenite here alpha ferrite. So in between. alpha ferrite plus gamma austenite right now second point or second reaction you can say you take two reactions so gamma austenite that will be converting into alpha ferrite plus cementite and that would be called as a perlatic transformation so that will be the eutectoid transformation so at that point it forms only pearlite like this so here it will be the alpha ferrite and pearlite so in between alpha ferrite plus pearlite After the 0.8% carbon there is no existence of the alpha ferrite.
So alpha ferrite now it would be converting into the cementite. So from 0.8% carbon to 2% carbon that forms. So pearlite plus Fe3C means cementite.
Right. So now third reaction or third point and that will be eutectic reaction. reaction point but you can see liquid that will be converting into gamma austenite plus cementite and that will be called as a lead butyrate. So here I am taking the point reaction for eutectic transformation. So here liquid will be converting into two different solids.
So gamma austenite plus ladyburet here ladyburet and from this side ladyburet plus fe3c that means cementite Now for this liquid that will be converting into gamma austenite. So before the 4.3% of the carbon there is an enrichment of the gamma. So liquid plus gamma austenite. And after the 4.3% of carbon, carbon that will be converting into cementite. So liquid plus Fe3C.
Now this region, this pearlite it will be transforming at room temperatures. So pearlite plus gamma. austenite plus transform ladyburite and from this side fe3c cementite or you can say and transformed leadaburite.
Right so these all are related with the iron carbon diagrams. Suppose I want to talk for the 4.8 percentage of carbon so that will be representing as a hypo eutectoid reaction and 0.8% of carbon you can say eutectoid reaction after 0.8% carbon to 2% carbon that will be called as a hyper eutectoid transformation. Similarly after 2% carbon to 4.3% carbon that will be representing because that will be the category of eutectic points. So hypo eutectic transformation and after 4.3% carbon to 6.67% carbon, hyper eutectic transformation.
So in that case basically Up to 2% carbon so I want to say that would be the category of steel materials and from