Microstructure Analysis and Hardness Test of Branch With Reinforced Pad After Close Range Multilayer Welding Spool 4I84-0008-01-1 Line Projects Dianita Wardani, Budi Prasojo, Widya Emilia, George Endri
Politeknik Perkapalan Negeri Surabaya
Abstract
Project Line spool fabrication is a pipe manufacturing project for factories chemistry in Cilegon where there are many spool fabrication problems, especially in spool with number 4I84-N-0008-01-1. This welding experienced problems in the form of microstructural defects that impact the hardness of the material in that area Reinforced bearings. This defect causes the material to not meet standards The maximum hardness is determined by the project owner^s specifications, so that repairs must be carried out with Post Weld Heat Treatment (PWHT). Study It uses the Vickers Hardness testing method to evaluate material hardness, with a maximum acceptable hardness criterion of 250 HV. Apart from that, metallographic testing was also carried out to understand the changes microstructure due to the adjacent multilayer welding process. Testing Metallography was performed according to ASTM E3 standards, with the aim of finding influence of heat treatment on welding. The research steps include initial identification, data collection, test preparation, metallographic testing and Vickers hardness, as well as data processing. Primary data was obtained through interviews with the Workshop Team and Quality Checking team, while data secondary includes Material Data and NCR spool. The test results show that the hardness of the material after close-range multilayer welding is still deep acceptable hardness range, despite changes in microstructure significant in the HAZ (Heat Affected Zone) region. The end of this research is that multilayer close welding has the potential to affect the microstructure and material hardness. However, the material still meets standards determined without the need for additional Post Weld Heat Treatment (PWHT).
