The influence of nitrogen, phosphorus, sulphur and nickel on the stress corrosion cracking of austenitic FeNiCr alloys

Abstract

From the results of the stress corrosion cracking tests it is evident that austenitic alloys with a phosphorus content <0.01%, and with a nickel content between 33 and 38% exhibit a high resistance. Alloys with a phosphorus concentration <0.005% and a nitrogen concentration <0.006%, even a melt with reduced nickel content, exhibits resistance to stress corrosion cracking. Reduction of the nickel content <25% causes the susceptibility to stress corrosion cracking to appear again at very low phosphorus and nitrogen concentrations. An increase of phosphorus content >0.01% causes a strong increase in stress corrosion cracking susceptibility of alloys with a nickel content in the range 33–38%. With a nickel content of ∼ 35%, an increase of nitrogen concentration to ∼ 0.15% also produces a significant effect on stress corrosion cracking susceptibility. A sulphur content up to 0.033% does not produce a significant effect on stress corrosion cracking.