Stainless steel powder 434L is a low-carbon ferritic steel powder, in mildly corrosive environments or atmospheric exposures, have corrosion resistance approaching that of some nickel stainless steels. These alloys are oxidation resistant at elevated temperatures. Type 434 stainless steel alloys are ductile and do not work-harden readily.
The toughness, defined as resistance to crack propagation or notch strength, of ferritic steels is relatively low, and the ductile-to-brittle transition temperature is at or above room temperature.
The corrosion and oxidation resistances of the ferritic steels are directly related to their chromium content. The 17% Cr 434 steel alloys have good corrosion resistance to atmospheric conditions.
These alloys are used in a variety of applications where corrosion resistance is more important than strength.
Corrosion Resistance
These alloys are resistant to attack in a wide variety of corrosion media.
Type 434 alloy powder resist oxidation at temperatures up to 1600°F for intermittent service, and from 1450°F to 1500°F for continuous service. The scale formed is tightly adherent and not easily shed during sudden temperature changes. Since the rate of oxidation is greatly affected by the atmosphere involved, by the heating and cooling cycles, and by the structural design, no actual data can be presented which would apply to all service conditions.
These low carbon stainless steel 434 alloys become susceptible to intergranular corrosion in certain environments when the air is cooled from temperatures about 1500°F. The sensitivity to intergranular attack may be accomplished by a decrease in ductility. Normal corrosion resistance and ductility are restored by annealing.
Ferritic stainless steel powdered metallurgy (P/M) technology is specified for longer-term performance and reliability. Good atmospheric and saline corrosion resistance, hot oxidation resistance and elevated temperature yield strength, at the most economical costs are key reasons for using 400 series stainless steel water atomized powders to make automotive components.
Typical automotive components requiring 400 series powders include rear-view mirror mounts, sensor rings, exhaust flanges, exhaust support brackets, and seals.