Stainless Steel > Wire > AM-350

Alloy 350 is a chromium-nickel-molybdenum stainless steel which can be hardnened by martensitic transformation and/or precipitation hardening. It has been used for gas turbine compressor components such as blades,discs,rotors,and shafts, and similar parts where high strength was required at room and intermediate temperatures. Depending upon the heat treatment,alloy 350 may have an austenitic structure for best formability,or a martensitic structure with strengths comparable to those of martensitic steels. The alloy normally contains about 5 to 10% delta ferrite. The corrosion resistance of alloy 350 approaches that of the chromium-nickel austenitic stainless steel

Corrosion Resistance

Alloy 350 has corrosion resistance superior to that of other quench-hardenable martensitic stainless steels. It has shown good corrosion resistance in ordinary atmospheres and numerous other mild chemical environments. Material in the double-aged or equalized condition is susceptible to intergranular corrosion because of the precipitation of chromium carbides. When the alloy is hardened by treatments employing sub-zero cooling as in the following paragraph,it is not subject to intergranular attack. The treatment for optinum stress-corrosion resistance of alloy 350 is as follows:

Heat to 1850/1950 °F(1010/1066 °C),cool rapidly to room temperature,sub-zero cool 3 hours at -100 °F(-73 ° C) reheat to 1700/1750 °F(927/954 °C)about 90 minutes per inch(25.4 mm)of thickness,cool rapidly to room tempertature,sub-zero cool 3 hours at -100 °F(-73 °C),then temper 3 hours at 1000 °F(538 °C). For optimum corrosion resistance,surfaces must be free of scale and foreign particles and finished parts should be passivated.