When "Hydrogen Control" is specified for a manual metal arc welding project the electrode would normally be:
You would certainly recognize a hydrogen controlled flux electrode from its:
BS639/AWS Code Letter
You notice manual metal arc electrodes are being, stripped of flux, are being used as a filler metal wire for TIG welding. You would object because:
It is too expensive
The wire would be too thick
The metal composition may be wrong
The wire is too short
For open site manual metal welding the following equipment is available. Which would you choose for safe site working?
Single operator transformer
AC/DC composition power unit
Diesel engine driven motor generator
In MMA welding what parameter is used for control of penetration into the base metal?
iron powders in the coating
What type of characteristic is required for manual welding?
The weld metal deposit for MMA electrodes achieves its mechanical strength through:
The core wire
The flux coating
Iron powders with the flux coating
None of the above
What constituent is needed in the coating of an electrode to prevent the formation of porosity in the welding of a rimming steel?
Cellulose electrodes are often used when welding the root pass of pipes in the field because:
Hydrogen control is needed
There are iron powders in the electrode
Higher arc voltage can be obtained
Shorter arc length can be obtained
MMA electrodes can be grouped into three main types:
Basic, cellulose and rutile
Neutral, cellulose and rutile
Movement of the arc in MMA welding by magnetic forces is called:
Which of the following coatings is associated with welding?
The voltage necessary to maintain an arc during metal arc welding is termed:
Main supply voltage
Open circuit voltage
When MMA welding low carbon steel which electrode which electrode will give the greatest deposition rate?
Hydrogen controlled electrodes were developed principally for:
The prevention of porosity
The prevention of cracking
The enhancement of arc voltage
There ease of arc starting
A basic electrode would normally:
Have superior mechanical properties
Require baking before use
Not to be used on low carbon steels
Both A and B
MMA welding of low alloy steels is more likely to be performed with:
Iron powder electrodes
Basic hydrogen controlled electrodes
When manual metal arc welding low carbon steel, which electrode covering will give the greatest degree of penetration?
MMA welds made with damaged electrode coatings are subject to:
Excessive bead hieght