Astro 490 Premium Nickel Electrode

Description

GENERAL CHARACTERISTICS:

Specially formulated coating gives a pulsed arc for low temperature welding of grey cast irons. When properly applied, the arc will penetrate surface skin and contaminants to produce a porosity free weld. Stress cracks are almost always avoided and welds are machinable.

TYPICAL APPLICATIONS:

Low temperature welding of cast iron in all positions. Repairing breaks and cracks in engine blocks, gear housings, machine bases and frames. Ideal for filling holes and building up worn or missing sections which must be machined to final dimension after welding. Also for joining cast iron to steel, iron, stainless steel, copper, Monel etc.

QUALITIES:

• Tensile strength: Up to 50,000 P.S.I. (350MPa)
• Yield strength: Up to 40,000 P.S.I. (275MPa)
• Elongation: Approx 3%
• Hardness (HB): Approx 175-225 Brinell
• Colour match: Similar to cast iron
• Deposit: Magnetic

PROCEDURES:

Clean welding area by grinding – remove surface skin and sharp edges, use ‘U’ or double ‘U’ preparation (90 degrees) Preheat not necessary, however warming to 200C will produce a softer, more machinable deposit.

Select lowest possible amperage, hold electrode vertically and maintain a short arc.

Butter thin layers (approx 5-7mm wide) and ensure bead is no longer than 10 times the diameter of the electrode.

NOTES:

Do NOT overheat workpiece (hand warmth), weld on different spots, peen and brush thoroughly.

On subsequent layers, always strike arc on the existing seam, and not the base material.