Welding of aluminum-killed steel for low temperature service used for LPG tankers and LPG storage tanks.

Characteristics on usage:

NB-1 is an extra low hydrogen type covered electrode for all-position welding of aluminum-killed steel used at low temperature.

The weld metal contains about 1.5% Ni.

Notch toughness of weld metal at low temperature (-40~-50C) is stable and good.

Notes on usage:

1. Pay attention not to exceed proper heat-input because excessive heat-input causes deterioration of impact values of weld metal.

2. Dry the electrode at 350~400C for about one hour before use.

3. Adopt back step method or strike the arc on a small steel plate prepared for this particular purpose to prevent blowholes at the arc starting.

4. Keep the arc as short as possible.