locomotive

Hi guys,A locomotive is a railway vehicle that provides the motive power for a train. Trains are pulled by powerful engine units called locomotives. In a steam locomotive, pressure from the steam moves a piston back and forth, which turns the wheels via a connecting rod. In a diesel electric locomotive, air is drawn in to the engine cylinders and is compressed to increase its temperature; a small amount of diesel fuel is then injected in to it. The resulting combustion drives the generator to produce electricity, which is fed to electric motors. In electric locomotives, electric current is picked up either from a overhead cable via a pantograph, or from a third rail. Thank you.

liver

Hi friends,
The liver is an organ in the abdomen. It is part of the gastrointestinal system. Nutrients absorbed from the intestine reach the liver via the portal vein, and are processed and redistributed according to the body’s requirements. Hence the liver regulates the levels of glucose, fats, and proteins in the blood. It also removes toxins, breaks down ageing red blood cells, and produces bile, which is stored in the gall bladder for discharge in to duodenum where it assists the absorption and digestion of fats. Thank you  

Sizzling Trisha

Hi Trisha Fans,

These are the recently released photos of sizzling Trisha in her forthcoming films Enjoy seeing it.

Igneous rock

Hi friends,
Welcome to my blog once again. Igneous rocks originate deep in the earth. They erupt from volcanoes as magma and cool or solidify as they rise to the upper layers. Basalt is an igneous rock and so is granite, a very a hard rock often used in building. Pumice stone is a soft igneous rock that is ejected from volcanoes. As it cools, it often fills with so many air bubbles that it floats in water. Thank you. 

Cold working operation

Hi friends,
Cold working does not necessarily mean literally what it says, it is true that many metal working processes are carried out at ambient temperature and these can certainly be termed cold working. However, metal working that is carried out at a temperature much higher than that revealing on the shop floor can also be described as cold working. The upper temperature limit of cold working varies with the metal and its metallurgical condition before working, but for steels cold working is generally considered to be between ambient and about 300 c. Significant work hardening takes place, and this severely limits the amount of plastic deformation that can occur before the material ruptures. To overcome this, if all the desired geometric changes cannot be achieved in one operation, the material must be partly changed and then annealed to eliminate the stress introduced by the work hardening. After annealing the work piece can then be safely subjected to a second cold working operation that will, hopefully, permit reduction to the final desired geometry. Cold working processes generally produce repeatable accurate components with a good surface finish. Unfortunately, cold working forces are very much higher than those required for hot working and unwanted residual stress are usually present after the final stages of working. If they are significant they tend to be released during subsequent machining of the part needs to be annealed before machining to remove these locked – in stresses. Any distortion that occurs during annealing is of no consequence as its geometrical effects will, of course, be removed during machining of the part. Thank you.

hot working operation

Hi folks,
A metals recrystallization temperature is not quite as easy to determine as its melting point, because it is influenced by such factors as the level of internal stress that exists in the metal before heating, the alloys contained within the metal and its melting point .for many metals the recrystallization temperature is between 0.4 and 0.5 of the materials absolute melting point (k). Depending upon carbon content, for most steels it is generally in the region of 500 – 700 C. as can be seen from ambient, with aluminum being at just 150C. Thus, hot working does not necessarily imply that the temperature of the metal being worked is above ambient, although in most cases it is. And an important characteristic of hot working process is that the metal behaves in a perfectly plastic manner. Therefore the metal becomes neither internally stressed nor work hardened, so an unlimited amount of hot working can be performed on it without at a lower temperature. Hot working causes slag porosity and other inclusions inherent to some degree in most cast metal to be deformed and broken up into insignificantly small pieces. Also, the coarse granular structure typical of cast metals is realigned and a large number of smaller grains are formed. The effect of this is to impart a degree of toughness to the worked materials, although hardness and density are unchanged by hot working. Thank you.

Production Flow Analysis

Hi friends,
Production Flow Analysis is a method identifying part families and associated grouping of machine tools. It does not use a classification and coding system and not use part drawing to identify part families. Instead, PFA used to analyze the operation sequence and machine routing for the parts produced in the given shop. It groups parts with identical or similar routing together. These groups then used to form logical machine cells in a group technology layout. PFA procedure is Data collection-Decide on the scope of the study and collect necessary data, Sorting of process routing – assemble the parts into groups to the similarity of their process routings, PFA chart- the processes used for each pack is displayed graphically on a PFA chart, Analysis-Rearrange the data of PFA chart into a new pattern which brings together packs with similar routings. Thank you