Effect of alloying elements on the cracking resistance of structural steels intended for low-temperature application

The cracking resistance of structural chromium-nickel-molybdenum steels are analyzed under delayed fracture conditions. The fracture surfaces of steel specimens and the effect of molybdenum and impurities (phosphorus, tin) on their cracking resistance are investigated by Auger electron spectroscopy and emission spectral microanalysis. The positive influence of molybdenum on an increase in the cracking resistance is shown to increase as its content increases to 0.6%; molybdenum does not influence the cracking resistance at its content of 0.6–0.98%, and this effect decreases at a molybdenum content higher than 0.98%.