General Characteristics

The main difficulty in gas welding bronze is the burnout of impurities, especially tin. Tin starts to form balls at 500 to 600 °C, which burn off to form tin oxides. Foam forms on the surface of the weld pool as the tin evaporates, the weld becomes porous, and the strength of the metal decreases. Welding aluminum bronze is difficult because of the refractory aluminum oxide, which is difficult to remove from the weld pool. In addition, bronze becomes brittle when heated above 500 °C and loses ductility. When welding, castings are heated unevenly - this can lead to significant internal stresses and cracking. Therefore, it is recommended to weld cast bronze items with preheating up to 450 °C. Do not lift and turn hot items during welding, because fragile bronze in such state can crack.

Filler material

As such, a composition similar to the basic one is taken. As a rule, cast rods are used, Ø 5-8 mm and a length of 400-500 mm. It is better if their composition will include phosphorus (up to 0.4%), as it prevents oxidation of tin, thus the seam is poreless. Before welding the surface of the rods should be thoroughly cleaned.

Flux

It can be used in the same way as in copper welding. When welding aluminum bronze takes the same flux as for welding aluminum alloys (sodium chloride - 20%, sodium fluoride-15%, potassium chloride-45%, barium chloride - 20%), as this flux can remove the resulting aluminum oxides.

Special features of technology

The burner flame must be normal. Excess acetylene can lead to pores in the weld, and excess oxygen promotes oxidation of tin, copper and other components of the bronze. Welding should be done quickly, without interruptions. To do this, a second torch is used (as in copper welding), which heats the metal, moving ahead of the welding torch. During welding, flux is continuously introduced into the weld pool by dipping the end of the rod. The end of the flame core of the torch should be at a distance of 6 to 10 mm from the surface of the molten metal. The power of the tip of each torch should not exceed 100 l / h per one mm of metal thickness. At the end of welding part is heated to 450-500 ° C and cooled in water.

Buy, price

Evek GmbH sells bronze products at an optimal price. It is formed taking into account the rates at the LME (London Metal Exchange) and depends on the technological features of production without additional costs. All batches of products have a certificate of quality for compliance with the standards. With us you can buy in bulk the most various products for large-scale productions. The wide choice, exhaustive consulting of our managers, reasonable prices and timeliness of delivery determine the face of our company. There is a system of discounts for wholesale purchases.