Welding Cylinder Head: The Effect of Filler Variations and Post Weld Heat Treatment (PWHT) on Microstructure and Mechanical Properties on TIG Welded Cast Iron FC 250

Wikan Jatimurti,Mas Irfan P Hidayat,Meilati Pasca Muna,Rochman Rochiem,M Anis,B Munir

doi:10.1051/matecconf/201926901011

Wikan Jatimurti, Mas Irfan P Hidayat + Show 4 more

Open Access

https://doi.org/10.1051/matecconf/201926901011

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Abstract

Cylinder head made from grey cast iron, is one of critical engine part which work on high temperature and pressure. The condition which occurs continuously during engine operation causes wear which identified as a fretting failure. Therefore repairing process is needed by using Tungsten Inert Gas (TIG) welding. By considering the working condition and the materials, welding parameters are used 140A current, 100% Argon, DCEP and preheat at 250°C. The welding process is done on specimen sample of cylinder head which fretting failure by using Ni-CI, NiFe, NiFe-1 dan 308L filler variation for each specimen and done by PWHT at temperature 650°C which holding time 90 minutes. Visual test, macroscopic test, microscopic test and hardness test already done in this research. The results are there is no defect such as crack, porosity, undercut, and lack of fusion on the visual and macroscopic test. On microscopic test, there is the brittle phase (martensite) in HAZ at Non-PWHT specimen, but after PWHT the martensite transform became martempered phase. FC250 standard hardness value is about 170-235HB, and the result is the hardness value of non-PWHT specimen higher than the standard in HAZ, and the high hardness value of PWHT specimen on weld metal by using NiFe, NiFe-1 and 308L. So from the filler variation, Ni-CI filler with PWHT is on standard either on phase or on hardness value

Highlights

In an internal combustion engine, cylinder head is a crucial component of combustion engine because cylinder head was located on hotspot which is works at high temperature and high pressure continuously[1]
The function of Post Weld Heat Treatment is to refine martensite in weld metal and Heat Affected Zone (HAZ), which aims to reduce hardness and increase toughness and reduce the residual stress that occurs during the welding process
The filler variation does not affect the microstructure formed in the base metal and HAZ regions, but it affects the fusion line and weld metal regions where the microstructure formed depends on the filler composition used

Summary

Introduction

In an internal combustion engine, cylinder head is a crucial component of combustion engine because cylinder head was located on hotspot which is works at high temperature and high pressure continuously[1]. An area is adjacent to HAZ where the heat on the weld area is high enough to cause the base metal to partial melt. This is the most critical area of the weld because in cooling, this area forms white iron (when held at high temperatures long enough carbon soluble) due to the high rate of cooling. The function of Post Weld Heat Treatment is to refine martensite in weld metal and HAZ, which aims to reduce hardness and increase toughness and reduce the residual stress that occurs during the welding process. XRD testing is done to determine the compound or the phase formed on the welding result

Experimental Procedure

Electrode Diameter

Conclusion

Welding by using Ni-CI filler and PWHT