Abstract :
Welding is a technique of metal grafting by liquefying some of the main
metal and filler metal with or without adding metal and producing continuous
metal. One of the most common problems in the use of steel as a base of
construction is that steel has fragile nature. This study aimed to identity the effect
of oil viscosity as a cooling medium to the hardness and microstructure of the
welded medium carbon steel strip plate.
This research used experimental research method and this research type
was quantitative research. To obtain the results on the analysis of hardness and
microstructure of medium carbon steels that have processed SMAW welding with
the variations of coolant medium, the data obtained were analyzed using
descriptive analysis by describing the comparable specimen of the specimens
differently during the manufacturing process until the test.
The effect of the difference in oil viscosity as a cooling medium can
affect the hardness of the material used as a specimen. The test showed an
increase in the hardness value of the material used. In the microstructure the oil
viscosity difference also caused the existing structure of the raw material changed
after welding and also made the new structure