SIL-TRODE

Description and Application

A silicon bronze welding alloy (UNS C65600) for the inert gas welding of copper-silicon, copper zinc, copper to themselves, and also to mild steel. Used extensively in the welding of galvanized steel. The silicon content of 2.8-4%, increases tensile rates. Silicon bronze also provides good corrosion resistance and has good weldability.

Silicon bronze is hot short and extreme care must be exercised to avoid overheating the joint which tends to cause cracking.

Chemistry

% (Filler Metal)

Copper........................................................Balance

Silicon..........................................................2.8-4.0

Zinc............................................................1.0 max.

Tin..............................................................1.0 max.

Manganese.................................................1.5 max.

Iron..........................................................0.50 max.

Aluminum.................................................0.01 max.

Lead.........................................................0.02 max.

Others......................................................0.50 max.

Mechanical Properties (nominal)

Tensile Strength, ksi..........................50(350 MPa)

Elongation, % in 2"..........................................40

BHN (500kg.)

1/4" deposit.....................................................80

Welding Procedure

With gas metal-arc welding, the weld matal should be deposited in stringer beads, maintaining a small molten pool to avoid  overheating the hot short silicon bronze base metal. Use argon gas for sheilding and relatively high welding travel speeds.

With the gas-tungsten arc welding process, welding is accomplished with dcen current and argon or helium gas sheilding. ACHF with argon gas sheilding may be used to take advantage of the arc cleaning action.

Preheat

Preheat sligthly to remove moisture. Interpass temperature should not exceed 150°F (66°C)

Specification

AWS A5.7 Class ER CuSi-A