Iron-based stainless brazing filler metals

The nickel-based brazing alloy BrazeLet BNi9 provides high strength joints when brazing stainless steel materials in vacuum or protective atmospheres (dry hydrogen or argon). The brazing alloy is typically used for brazing nickel-based superalloys and stainless steel components where high elevated temperature strength is important, such as gas turbines and solid-oxide fuel cells. It is well suited for repair brazing and diffusion brazing as B readily diffuses into the base materials leaving a ductile Ni-Cr matrix in the joint.

Höganäs’ unique and patented iron-chromium based stainless brazing alloy BrazeLet F300-20 offers excellent wetting properties and great corrosion resistance particularly developed for brazing of stainless steel materials in vacuum or protective atmospheres (dry hydrogen or argon). With excellent wetting properties, low brazing temperature and high corrosion and oxidation resistance it is a good choice for automotive and industrial heat exchangers. It is well suited for drinking water applications with strict requirements on metal ion leaching. Compared to nickel-based brazing alloys it offers a more attractive and stable cost. Compared to most of the standard nickel-based brazing alloys, BrazeLet F300-20 is able to fill larger gaps without brittle phase lines or cracks, which leads to a more reliable and safe brazing as well as more flexibility in part tolerances.

The water-based brazing paste BrazeLet F300DW-9007 can be used for dispensing applications, typically found on heat exchanger inlet and outlet tubes, housing to core joints and hole plates to tube joints. It dries quickly and sticks to all bevel and vertical positions without the need of pre-drying. It can be easily removed with water. The paste has a very low polymer content and the binder is specially designed to decompose cleanly at low temperatures, as to minimise need for furnace maintenance, while preventing pre-oxidation of brazing filler metal powder in marginal furnace atmospheres. It shows extremely good residue-free brazing results in both vacuum and continuous belt furnace brazing. 

BrazeLet F300DW-9007 properties allow reliable application in a wide speed range as a result of the dispensing equipment / automatisation as well as the needle diameter. The paste can be delivered in cartridges for use in automated applications or different sized cans. It can be frozen and brought back to room temperature for use without any damage to its properties.

Höganäs’ unique and patented iron-chromium based stainless brazing alloy BrazeLet F300-20 offers excellent wetting properties and great corrosion resistance particularly developed for brazing of stainless steel materials in vacuum or protective atmospheres (dry hydrogen or argon). With excellent wetting properties, low brazing temperature and high corrosion and oxidation resistance it is a good choice for automotive and industrial heat exchangers. It is well suited for drinking water applications with strict requirements on metal ion leaching. Compared to nickel-based brazing alloys it offers a more attractive and stable cost. Compared to most of the standard nickel-based brazing alloys, BrazeLet F300-20 is able to fill larger gaps without brittle phase lines or cracks, which leads to a more reliable and safe brazing as well as more flexibility in part tolerances.

The brazing paste BrazeLet F300DW-9201 can be used for dispensing applications, typically found on heat exchanger inlet and outlet tubes, housing to core joints and hole plate to tube joints. It can be dispensed by using standard air pressure dispensing units. For better precision, screw dispense units are recommended. The paste sticks on all bevel positions without the need of pre-drying but is easily removed using water. The paste formulation offers the highest metal content of our standard dispensing pastes.

BrazeLet F300DW-9201 properties allow reliable application in a wide speed range as a result of the dispensing equipment / automatisation as well as the needle diameter. The paste can be delivered in cartridges for use in automated applications or different sized cans for refilling of smaller cartridges for manual applications. For best performance, it is recommended to first stir the paste.

Höganäs’ unique and patented iron-chromium based stainless brazing alloy BrazeLet F300-20 offers excellent wetting properties and great corrosion resistance particularly developed for brazing of stainless steel materials in vacuum or protective atmospheres (dry hydrogen or argon). With excellent wetting properties, low brazing temperature and high corrosion and oxidation resistance it is a good choice for automotive and industrial heat exchangers. It is well suited for drinking water applications with strict requirements on metal ion leaching. Compared to nickel-based brazing alloys it offers a more attractive and stable cost. Compared to most of the standard nickel-based brazing alloys, BrazeLet F300-20 is able to fill larger gaps without brittle phase lines or cracks, which leads to a more reliable and safe brazing as well as more flexibility in part tolerances.

The brazing paste BrazeLet F300P-9012 is typically in use for printing thick paste layers of about 0.2 to 0.6 mm on flat parts or on top of structured parts by use of screens or stencils. A typical application is printing of paste on hole plates of tube bundled heat exchangers. The use of rubber squeegees is recommended. Reliable printing requires precise positioning fixture tool by use of vacuum table or clamping device. Typical printing speed is 100 mm/s. Thin printing lines should at least have a width twice the printing thickness and the small dots diameter should be three times the printing thickness or greater. Printing accuracy is very precise as the paste maintains its shape during drying. 

The solvent based BrazeLet F300P-9012 increases productivity wherever drying of the paste is an issue. It has no settlement, and no stirring is needed in the equipment. However, when opening a can from stock it is always recommended to stir the paste. The printed parts can be dried with standard drying process (hot air) at 120 – 170 °C. Here, the drying time needs to be established as it varies depending on thermal mass, parts design and the used furnace. After drying, the paste has excellent adhesion to the metal sheet.

Höganäs’ unique and patented iron-chromium based stainless brazing alloy BrazeLet F300-20 offers excellent wetting properties and great corrosion resistance particularly developed for brazing of stainless steel materials in vacuum or protective atmospheres (dry hydrogen or argon). With excellent wetting properties, low brazing temperature and high corrosion and oxidation resistance it is a good choice for automotive and industrial heat exchangers. It is well suited for drinking water applications with strict requirements on metal ion leaching. Compared to nickel-based brazing alloys it offers a more attractive and stable cost. Compared to most of the standard nickel-based brazing alloys, BrazeLet F300-20 is able to fill larger gaps without brittle phase lines or cracks, which leads to a more reliable and safe brazing as well as more flexibility in part tolerances.

The brazing paste BrazeLet F300R-9003 can be used for roller coating fins or structured plates, typically found in flat heat exchanger designs. Depending on type of roller used the paste can be applied with thin layers either on top or on the side of the fin tips. Gap size between the paste roll and the scraper of 0.08 – 0.12 mm is recommended. The amount of paste is controlled by weight and is a function of the fins or structured plate design. BrazeLet F300R-9003 properties allow reliable application in a wide range of coating speeds, tested with good results from 3 m/min up to 20 m/min. The oil-based paste ensures reliable coating over time without drying on the roll. BrazeLet F300R-9003 has higher metal content and lower binder content compared to standard roller coating pastes, which decreases packaging and transportation needs for the same amount of brazing filler metal.

The coated fins can be dried with standard drying process (hot air) at 120 – 170 °C. The drying time depends on thermal mass, parts design and the used furnace and thus needs to be established. When dried, the paste has excellent adhesion to the metal sheet.

Höganäs’ unique iron-chromium based stainless brazing alloy BrazeLet F86 provides high strength joints when brazing stainless steel materials in vacuum or protective atmospheres (dry hydrogen or argon). The brazing alloy is particularly well suited for brazing heat exchangers with strict requirements on corrosion resistance and metal ion leaching, for example in drinking water or purified water applications, and it is completely copper free. Compared to nickel-based brazing alloys it offers a more attractive and stable cost. Compared to most of the standard nickel-based brazing alloys, BrazeLet F86 is able to fill larger gaps without brittle phase lines or cracks, which leads to a more reliable and safe brazing as well as more flexibility in part tolerances.