Temper embrittlement of 15Cr2NiMoV steel

Eight ingots of 50 kg weight were cast to analyze the influence of P and Sn upon the properties of 15Cr2NiMoV steel. Four levels of Sn content, i.e. 20, 70, 150 and 250 ppm, each with two levels of P, i.e. 0.009 and 0.019%, were thus obtained. The used final heat treatment of test rods should evoke temper brittleness. It was found that the influence of Sn on the disposition to temper brittleness in 15Cr2NiMoV steel is not so high as that of P, which is dominant and at least twice as high. The effect of Sn alone is felt at contents about 200 ppm. An increase of P from 0.009 to 0.019% significantly promotes the effect of Sn on temper brittleness development. (author) 1 tab., 7 figs., 22 refs