ANALISA HASIL PROSES PERLAKUAN PANAS PADA PROSES PRODUKSI PEGAS ULIR JIS G4801 SUP-9A DI BALAI YASA MANGGARAI PT. KERETA API

• Main Author: BASTIAN , MAULIDIN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/10863
• Institution: Institut Teknologi Bandung

Manufacturing which is applicable for shaping the material can change the properties. In this assignment, writer did the research about the effect of heat treatment in coil spring (as boogie component) production process, product of Balai Yasa Manggarai P.T Kereta Api. Heat treatment intends to alter mechanical properties by diffusion or shear mechanism. In manufacture of coil spring, heat treatment is needed to increase Ultimate Tensile Strength for getting large E u ? ratio. Higher ratio of E u ? , will increase the life of spring. Materials that used in this research are hypoeutectoid steels JIS G4801 SUP-9A from 4 (four) different countries, China, India, Germany and Japan. The purposes of this research are to select the material that fit with JIS or AISI standard by analyzing materials and the products from their mechanical properties and microstructure. Beside that, this research intends to analyze manufacturing process which had been done by Balai Yasa Manggarai. The result shows that there is an altered of hardness and microstructure of spring material after processes. From literatures, mechanism which causes this strengthening is martensitic transformation, and it depends on temperature and time. From ductility values, E u ? ratio, and inclusion appearance, material M-11 originating from India is not very optional as spring material. Production processes in Balai Yasa Manggarai need good quality control and safety. With appropriate coil spring manufacturing processes, the product will meet the requirement for the best.