Mechanical Engineering

Annealing:- Annealing  Process :- Annealing is a heat treatment process by which the properties of steel are enhanced to meet machinability requirements. In this process Hypoeutectoid steels (less than 0.83% carbon) are heated above upper critical temp., soaked and cooled slowly and  Hypereutecoid (above 0.83%) are heated above lower critical temp., soaked and allowed to cool slowly. Annealing  Process Steps: 1.Heat material into the asutenite region (i.e. above 1600F) – rule of thumb: hold   steel for one hour for each one inch of thickness 2.Slowly furnace cool the steel – DO NOT QUENCH 3.Key slow cooling allows the C to precipitate out so resulting structure is coarse  pearlite with excess ferrite 4.After annealing steel is quite soft and ductile The purpose of Annealing is : 1)Reduce hardness and brittleness 2)Alter microstructure for desired mechanical properties 3)Soften...

HEAT TREATMENT •           It is a continuous process of HEATING, HOLDING AT A PARTICULAR TEMPERATURE FOR SPECIFIC TIME AND COOLING AT A PREDETERMINED RATE of metals to change their physical and mechanical properties, without letting it change its  shape. . The most common application is metallurgical. Heat treatment  could be said to be a method for strengthening materials but could also be used to alter some mechanical properties such as improving formability, machining, etc. It is very important manufacturing processes that can not only help manufacturing process but can also improve product, its performance, and its characteristics in many ways. •           Engineering properties are modified by  heat treatment  processes so that structural components are able withstand specified operating conditions and have desired useful life. The properties of steel can...

4 Things to avoid during interview If you've applied for a job and are lucky enough to score an interview, don't let one mistake ruin your chances of getting the job. A LinkedIn survey of more than 550 hiring managers found that when it comes to a job interview, even small mistakes can put a candidate out of the running. Here are four things you should never be caught doing, according to the survey: 4. Checking your phone Even the slightest glance at your phone during a job interview could cost you. More than one out of every three hiring managers polled said they would eliminate a candidate for looking at his or her cell. Checking your phone gives the impression that you're not totally there mentally and don't respect the person sitting right in front of you. Be safe and before the interview, turn your phone, and it's thousands of notifications, off. 3. Looking disheveled Nearly half of interviewers — 46 percent, to be exact — said they had el...

Most commonly asked Mechanical Interview Questions  ·          What happens if gasoline is used in a Diesel engine?Diesel engine will work ? No, It will not work,as the Compression ratio of Petrol engine is 6 to 10 & that of Diesel engine is 15 to 22 . Thus on such high compression, gasoline gets highly compressed & it may blast. ·          Which Mechanism is used in Automobile gearing system Differential mechanism ·           Why different types of sound are produced in different bikes though they say run on SI engine Engine specifications are different in different manufactures like as Bore Diameter(CC), Ignition timing.Also the exhaust passage take more responsible for sound. ·           Why entropy decreases with the increase in temperature? ds=dQ/T Entropy is inversely proportional to the temperatu...