Spectro Lab PDF

83 Spectro Lab The testing of sample that has to be further used or subjected for wheel manufacture is done at the spectro lab. The sample (solidified metal) for testing is obtained from the electric arc furnace to determine the composition of various metal constituent...

83 Spectro Lab The testing of sample that has to be further used or subjected for wheel manufacture is done at the spectro lab. The sample (solidified metal) for testing is obtained from the electric arc furnace to determine the composition of various metal constituents within the required range. The instrument or tester used for this purpose is ARL Metal Analyzer (M-402 optical emission spectrometer). ARL Metal Analyzer (M-402 optical emission spectrometer) PRINCIPLE: The principle of optical emission spectrometry involves applying electrical energy in the form of spark generated between an electrode (tungsten) and a metal sample, whereby the vaporized atoms are brought to a high energy state within a so called discharge plasma. WORKING: The polished sample is placed between two tungsten electrodes and an arc is struck. In doing so the electrons are excited. Inductively coupled plasma (ICP) is used as an excitation source. Optical emission refers to emission using spark discharge, direct current arc discharge or glow discharge for generating the excitation discharge. This method involves statistical processing of the spark pulse generated emission spectra obtained from spark discharges in an inert (argon) atmosphere. The excited atoms and ions in the discharge plasma create a unique emission spectrum specific to each element. Thus, a single element generates numerous characteristic emission spectral lines. Therefore the light generated by the discharge can be said to be a collection of the spectral lines generated by the elements in the sample. This light is split by a diffraction grating to extract the emission spectrum for the target elements. The intensity of each emission spectrum depends on the concentration of the element in the sample. Detectors (photo multiplier tubes) measure the presence or absence of the spectrum  84 extracted for each element and the intensity of the spectrum to perform qualitative and quantitative analysis of the elements. After detecting, the concentration of each element in the sample is displayed. The following element compositions are acquired:  Carbon  Manganese  Silicon  Phosphorous  Sulphur  Chromium  Nickel  Copper  Molybdenum  Aluminum  Vanadium  Lead  Titanium  Tin  85 The optical emission spectrometer offers rapid elemental analysis of solid metal samples, making it indispensable for quality control in steel making processes. It offers fast and accurate metal analysis. ADVANTAGES/BENEFITS:  Stability, accuracy, precision and low detection limits.  Robustness and reliability.  Easy integration to increase productivity. HYDROGEN TESTING MACHINE: The presence of hydrogen and other supplementary gases is tested using this machine. The working principle is based on Wheatstone bridge. A Wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance. It consists of four resistors where three resistors of known resistances are used to determine the unknown resistance. At the point of balance the ratio of the opposite resistances are equal. In working, nitrogen gas is constantly supplied for same resistance in all arms. Where the gas pass through Anhydrone. Based on normal distribution, the constant rate of hydrogen diffusion is determined.  86 Conclusion This internship provided us with an opportunity to learn the implementation of theoretical concepts on a large scale. Not only were the technical concepts and machine equipments were interesting to learn, but the communication and connectivity of work flow within RWF was thought provoking. RWF uses 95% of PLC (Programmable Logic Control) and advanced processes use CNC (Computer Numerical Control). If provided there was more time, utilization of it in learning more details of CNC programming and flow of logic in PLC could have been achieved. None the less, the working of Long Forging Machine was fascinating. The machine was power driven and the capacity of the machine to plastically deform the axle was good. The most interesting concept in Wheel Shop was Electric Arc Furnace. Unlike many other furnaces, the charge is directly exposed to an electric arc. The process of melting the charge using the furnace is distinct. Also, the magnaglo testing was interesting to see in application. The EOTs (Electrical Overhead Travelling Crane) were very helpful and had several applications and was working at every step in the manufacturing unit. The EOT was essential and it was a good experience to learn their mechanisms.