การตรวจสอบกลสมบัติและปริมาณธาตุคาร์บอนในเหล็กหล่อจากผู้ผลิตในจังหวัดขอนแก่น

Abstract

The aim of this report is to investigate the mechanicalproperties of cast iron from Sin Peun Maung and Chan Tai lekfoundry in Khon Kaen province. The mechanical properties are tensi1 estrength, impact trength, percent.age elongation and hardness, to be used as mechanical design data, At the same time the microstructure of cast iron was inspected in order to idenf ify it. The experiment was based on the theory of probability and statistics was used to evaluated the mean value and standard deviation of the mechanical properties of the cast iron, Three sets of samples were calculated and 95% confidence limits were attached to the mean. The experimental results were tested for assumption of morality by using histogram and Chi-square test

It could be concluded from the experiment that the cast iron had the standard of gray cast iron and the 95% confidence limits for the tensile strength (the classification o f general cast iron ) was given by 208.17 ± 12.11 N/mm2 , the Rockwell hardness was given by 97.95 ± 1.28 R_B,  the percent elongation was given by 1.21 ± 0.17 but approximate value for the brinell hardness was given by 210.16 ± 9.26 H_B, the impact strength was given by 41.00 ± 2.35 N-m and can be used for small or medium application with light shock.