Mechanical tools

. the principle of hardening . the effect of the carbon content in hardening . the process of hardening . the tempering of steel . the purpose of temaparing Introduction If a piece of steel is heated to a sufficiently high temparature, all the carbon will be dissolved in the solid iron to form the solid solution, austenite of the steel. When it is slowly cooled, the change in the arrangement of the iron atoms will cause a solid solution can only contain up to 0.006% carbon, and so the excess carbon will be forced to leave the solid solution, and produce cementite. This will, with ferrite, form a laminated structure called pearlite. The principle of hardening If steel is cooled rapidly (quenched ) the excess carbon will not have sufficient time to leave the solid solution with the  result that it will be trapped in the iron, and so cause an internal distortion. This internal distortion is the cause for the increase in the hardness of steel with a corresponding reduction in its stren...

. effect of carbon on the mechanical properties of steel. Steel  can be defined as an alloy of carbon and iron, in which carbon is in a combained state. The carbon content is a very important factor to get the desired properties of steel. Carbon Carbon is a very important constituent of steel. The addition of carbon  at varying proportions modifies the characteristics of iron and makes it harder, stronger and of greater use in the engineering industry. Slight variations in the carbon content of steel leads to great differences in the properties of steel. Depending upon the properties they are put to different uses. At room temparature in the annealed condition plain carbon steel contains three main constituents. -ferrite -cementite -pearlite Ferrite is a very weak solid solution of carbon and iron with about 0.006% carbon. This is a very soft and ductile constituent. Pearlite contains alternate layers of ferrite and cementite. This laminated structure makes pearlite stronger. ...