Inquirer:- Naval Brass (UNSC46400) to Naval Brass (UNSC46400) welding possible ?
Reply:-
Naval Brass (UNSC46400) is a copper-zinc alloy that contains approximately 60% copper, 39% zinc, and small amounts of tin and lead.
From the metallurgical point of view, the presence of Zinc in the Naval Brass can potentially cause porosity in the weld because Zinc is a volatile element that can evaporate during the welding process and form gas pockets or porosity in the weld. Suitable ventilation precautions must be taken before welding to deal with both zinc fume, which is toxic in nature When welding Naval Brass, it is important to use appropriate welding techniques and parameters to minimize the risk of porosity.
Both , GMAW & GTAW can be used to weld the Naval Brass to Naval Brass with 100 % Argon shielding and/or 75/25 Argon-helium combinations. Filler metals for MIG or TIG welding brasses should not contain zinc. This is because the zinc tends to vaporize in the arc, leading to zinc loss and porosity in the weld.
A common choice for welding brass is a silicon bronze filler metal. Silicon bronze, such as AWS A5.7 ERCuSi-A, is often used for Gas Tungsten Arc Welding (GTAW), or TIG welding, of brass. This filler metal offers good color match and mechanical properties.
I am rather thankful to an expert Mr. Savio Dias from ASVOTECH , Mote Mor , Brazil for bringing to my notice some typo correction made with the previous draft & suggesting me with a choice of filler metal mentioned above.
One way to minimize the risk of porosity is to use low heat input and slow travel speed during welding. This can help reduce the amount of zinc that vaporizes during welding and prevent the formation of gas pockets. Preheating the materials before welding can also help reduce the risk of porosity by reducing the cooling rate and allowing more time for gases to escape.
For more information, readers can go through the references mentioned below.
A procedure qualification test is highly recommended.
Hope this suggestions might help !
Source:-
Naval Brass – Properties and Applications: This technical data sheet by Sequoia Brass & Copper
https://www.twi-global.com/technical-knowledge/faqs/faq-how-can-i-weld-naval-brass
(https://weldingmaterialsales.com/catalog/ercusi-a-silicon-bronze/)
AWS Handbook Vol. 5
Welding Knowledge 