STATISTICAL QUALITY CONTROL OF CHEMICAL COMPOSITIONS AND HARDNESS VALUES OF GREY CAST IRON IN FOUNDRY SHOP – AJAOKUTA STEEL COMPANY LIMITED (ASCL)
Publication Date : 01/03/2017
Statistical Quality Control (SQC) analysis deals with quantitative data; it is also a scientific method of analysing masses of numerical data so as to summarize the essential features and relationship of data in order to generalize from the analysis pattern behaviour, particular outcome or future tendencies. This research work focused on the use of statistical quality control to determine the chemical compositions and hardness values of grey cast iron in the Foundry Shop with a view to detecting and eliminating non -random (sporadic) variations in production process. The process monitored the performance of the Chemical compositions and hardness values of grey cast iron periodically by examining sample units of output. The analyzed samples and data collected for critical characteristics were determined to ascertain if they shifted away from the purely random pattern. Ten samples were collected and analyzed with a SPECTRO Analytical Instrument in the Quality Control and Materials Analysis in the Foundry Shop of the Company, the chemical compositions were determined and the same samples were also used for hardness values which were also determined with the use of Brinell Machine in the Mechanical Repair Shop of the company. Two control charts (X and R) were used to determine the performance and to indicate if the process remained in control and where there are variations, these will serve as early warning system for the information of the management that something odd has probably happened to the production process.
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