Brazing is a metal joining process that requires a filler metal to be heated above its melting point and distributed between two or more close-fitting parts via capillary action. The filler metal is heated to slightly above its melting temperature. It then flows over the base metal and is cooled to permanently join the pieces together with a metallurgical bond.
There are eight variables that determine a successful brazed joint.
Four Pre-braze Fabrication Variables
Four Brazing Process Variables
Poor yields through brazing can be traced to deficiencies in one or more of the above variables.
Annealing is a heat treatment process that removes work hardening stress from steel by restoring the grain structure. Annealing is commonly used as a treatment to prevent cracking in components exposed to cyclic and other stresses and for parts that will undergo further metalworking processes.
Brazing and annealing work requires high temperatures, oxidation of the metal surface occurs in oxygen-containing atmosphere.
Oxidized surfaces form weaker bonds with the braze alloy and damage the corrosion resistance properties of stainless steels. Atmospheres blanket the parts in the furnace. Only pure atmospheres support consistently high yields and accurate defect root cause analysis.
When metals are exposed to oxygen, oxides form from oxygen atoms that attach to the metal. The oxides that form prevent the molten alloy from metallurgically joining to the metal. Also, oxides can weaken or destroy the corrosion resistance properties of stainless steel.
A bright finish on brazed and annealed parts is direct visual confirmation of the pre-braze cleanliness of parts and the quality of the atmospheres used. The brighter the part when it emerges from the furnace, the better. Clean parts and robust atmospheres are required to achieve maximum strength in brazed joints. An absolutely bright finish also assures you that the corrosion resistant quality of stainless steel parts has been preserved and maximized. You can really see the difference.
Continuous belt furnaces provide more uniform heating and cooling conditions versus batch processes. Process cycle times are shorter with minimal setup and changeover time and expense. The continuous furnace process generally requires no special tools, so startup and maintenance costs are lower. Higher quality, efficiency, and shorter cycle times make the continuous furnace process the most dependable source for Original Equipment Manufacturer’s applications.
Yes! Our process allows for brazing and annealing stainless steel parts and joining dissimilar materials. We can produce bright 400 series stainless brazed and annealed parts.
Yes. This is a natural advantage of brazing over other joining methods used for critical components. We regularly braze components with dissimilar base metals. Combinations of stainless and carbon steels are common.
Yes. Brazing is commonly used to join thinner gauge components such as tubing to heavier gauge components such as machined fittings. Often times these components are made from dissimilar base metals as well.
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