Ark Welding Covered Electrode

Product Description:

SF-0  SF SF-2SF-3

Arc welding covered electrode

SF-0  low hydrogen type    tip color  green

SF    low hydrogen type    tip color  violet

SF-2  lime-titania type      tip color  vermilion

SF-3  low hydrogen type    tip color  orange

APPLICATIONS : SF series is used for direct armour (hard facing) of cast iron metal molds.

CHARACTERISTICS

1. You can overlay directly to the cast iron with these electrodes, and can obtain the predetermined hardness at the 2-3rd layer.

2. The first layer changes to austenite and the 2-3rd layer changes to martensite.

3. You do not have to underlay, and can armour with one kind of electrode.

4. SF-0 , SF are good for armour to the cutting-edge because of their high hardness.

5. SF-2, SF-3 are good for the drawing die and for bead-laying.

NOTE ON WELDING OPERATION

1. It is effective for preventing the cracks to weld with preheating of about 100°C and with interpass temperature. Over 150°C preheating and interpass temperature should be avoided.

2. Adopt the arc starting plate method or the backstep welding method, because the start part tends to generate blowholes.

3. Weld with the current as low as possible. The arc length should be short, the weaving should avoid, and the bead length should limit to about 100 mm, and be sure to perform peening.

4. Re-dry the electrode for 30-60 minutes at 200-300°C before using.

TYPICAL HARDNESS OF WELDED METAL (as welded)

OPTIMUM WELDING CURRENT (AC or DC +)