Vanadium-Machining

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Machining:

High speed steel and carbide tools may be used to machine vanadium. Speed as well as tool angles and lubrication should be monitored to avoid galling.

Turning:

See general instructions for turning vanadium given in Table 1. These instructions are recommended as a starting point for working with vanadium. Adjustments to these procedures should be made to accommodate the different compositions of each vanadium alloy.

TABLE 1 - Tooling Recommendations for Machining Vanadium

Approach Angle                     15 o to 20 o

Side Rake                             30 o to 35 o

Side and End Clearance          5 o

Plan Relief Angle                    15 o to 20 o

Nose Radius                          0.020" to 0.030"

Cutting Speed                       60 to 80 ft/min with HSS

                                          250 to 300 ft/min with carbide

Feed, Roughing                     0.008" to 0.012"/revolution

Feed, Finishing                      0.005" maximum/revolution

Depth of Cut                        0.030" to 0.125"

Forming:

Vanadium has excellent cold working properties and can be forged, rolled or swaged at room temperature. Annealing is necessary after 80 to 85 % reduction of the cross sectional area. Vacuum annealing (<1 x 10-4 TORR) at 900 oC for 1½ hours will cause complete recrystallization of cold worked material. Vanadium is well suited to deep drawing and exhibits little springback.

 

Vanadium cannot be readily anodized like other reactive and refractory metals. Tantalum forms the best anodic films for capacitors but vanadium (although forming a protective oxide at low temperatures) will not respond to normal anodizing techniques. The principle oxide of vanadium is V2O5 which melts at 675 oC and is corrosive. Vanadium and its alloys must be fabricated below the melting point of the oxide or must be protected form an oxidizing atmosphere if higher temperatures are used.

Welding:

Vanadium is very reactive with the gases nitrogen, oxygen and hydrogen, therefore, precautions must be taken to protect any weld from these gases. TIG and plasma welding work well when precautions are taken to flood all surfaces of the weld (front and back) with inert gas (argon, helium).

 

Vanadium can be welded to most of the transition metals and their alloys. Welding with titanium, zirconium, niobium, tantalum and chromium as well as austenitic and ferritic stainless has been successful. Welding to other steels is possible if chromium is introduced into the weld at the time of welding.