Low-hydrogen electrode for high-temperature resistant surfacings on hot work

Steels exposed to impact, compression and abrasion.

Application field

On the strength of its great hardness, toughness and high-tempearture resistance, VHF-73G2 is employed for surfacing on machine components and tools exposed to abrasion and compression with moderate impact loads and operating temperatures up to 930ºF (550ºC).  These include dead centers, tongs, slide-and guideways, hot and cold cut-off attachments, valves, slides, hot shear blades, extrusion press pistons, dies, strippers, deburrers, sheet punching tools.

VHF-73G2 is also used to good advantage for the economic manufacture of cold and hot working tools.  In such cases the carrier steel must have a tensile strength of more than 158,000 psi (1100N/mm2) is used as parent metal for the tool.

Welding properties

The electrode welds in the horizontal or slightly rising positions.  The weld pool is easy to control and the slag is easily removed.

Heat treatment

Soft annealing           :1470-1525ºF (800-830ºC) 2 hours

Hardening                  : 2120-2260ºF (1160-1240ºC) / cooling in oil

Tempering                 : once or twice at 1000-1040ºF (540-560ºC) / 30 mins each          

Welding instructions

Bigger workpieces must be preheated to 750-1110ºF (400-600ºC) and kept at this temperature during welding.

A lower preheat temperature is enough for smaller work, because it is heated adequately by the arc.  Certain jobs on smaller workpieces may even be welded without preheating.  The depth of the build-up may amount to 15mm max.

Slowly cool in an oven or under asbestos after welding.  The weld can be machined only by grinding after it cools.  If other cutting operations have to be performed on a build-up weld, annealing is necessary.

 TYPICAL ANALYSIS OF ALL WELD DEPOSIT:

HARDNESS:

Hardness after welding: 55-58 HRC (600-650 Hv)

Soft-annealed                : about 25 HRC

Hardened                       : 64-66 HRC

RECCOMENDED CURRENTS: Ampere (AC/DC+)

WELDING POSITIONS:

FLAT, FILLET, VERTICAL UP

EXPORT Packing: 5Kg plastic container, then 4 5kg containers in master carton box

LOCAL Packing:  5Kg paper box in shrink wrapped plastic

Other special packaging can be accommodated as per request