Ni Based Manual Metal Arc Welding Electrode 1

[sujit123]

can any body tell me why Nickel based MMAW electrodes (Contains arround 90% Ni.) are usually choose upon gray cast iron as a buttering material before going to actual hardface deposition ?

 

[welding1]

Nickel fillers are relatively soft, and when diluted by parent material harden only to a limited extent due to the pick-up of iron, as they do not undergo any transformation on cooling. Because they are soft and ductile they are ideal as a buttering layer to absorb contracting stresses of subsequent weld layers.

However high phosphorous and sulphur levels in some grey irons, can contaminate the weld metal leading to solidification cracking.

Hope this answers your question

John

http://www.gowelding.com