what is exactly meant by tempering and how does it occur???
481So i mentioned-"TEMPERING IS MOSTLY FAVOURED IN INDUSTRIES"......read my answer carefully.....May be brittle steel is used for some purposes but mostlty tempering is done.....For e.g..Tipu Sultan's sword....See still so hard and didn't undergo any corrosion......Bbecause it was done by tempering.....
Asmita Chatterjee Thanx,i think this clears my doubt!nd nyc example!481Tempering is increasing the temperature of a substance to a certain amount and then cooling it slowly to get some properties........Another process quenching which refers to increasing the temperature of the substance to a certain amount and then cooling it rapidly.........Tempering is mostly favoured in industrial processes......
Now let me tell you why is it favoured in industries.....
When we are increasing the temperature of the substance,the molecules gain a certain amount of Kinetic Energy and start moving around rapidly and when cooled lowly,they arrange themselves in the best possible manner(REMEMBER WHAT RAJIV SIR SAYS-Everything in this world wants to be in the most stable state),while in quenching the rapid cooling makes distorted arrangement.
1I read it in my textbook that when quenching is done to steel,by heating it at a high temperature and then plunging it into cold water or oil,it becomes harder and more brittle....now why would they want to make steel brittle for???.....moreover, they have said that if quenched steel is reheated carefully to a regulated temperature between 220-300 degree celsius and then allowed to cool slowly,it retains its hardness but the brittleness vanishes....and this is called annealing.They have referred to the whole process of changing the properties of steel through heat treatment as "tempering".....now i dont understand wat is the use of quenching???why cant we directly do annealing??after all, in the end, the steel is becoming hard as well as not brittle....have they something wrong???if so,then please correct it!!