合金元素(Cr、Ni、Al、C)对Cr—Ni—Fe基合金高温硫腐蚀的影响

INFLUENCES OF ALLOY ELEMENTS (Cr, Ni, Al, C) ON THE SULPHIDATION ATTACK OF THE ALLOY BASED ON Cr-Ni-Fe AT HIGH TEMPERATURE

本文研究了含有不同合金元素的Cr—Ni—Fe合金在600℃、Ps_2为48mmHg的硫蒸气下的腐蚀行为,这些合金在此条件下出现了以硫化为主的高温腐蚀。腐蚀产物以多层金属硫化物为主,也夹杂着少量金属氧化物。结果表明:当C含量在0.15％～0.45％时,合金的腐蚀速度在含C量为0.3％时有最小值,合金元素Cr含量的提高,使合金的抗硫腐蚀性能加强,合金元素Ni含量的提高,降低合金的抗硫腐蚀性能;而合金元素Al的加入,由于在合金表面形成了保护性较好的Al_2O_3及CrS的混合层,则显著提高了合金的抗硫腐蚀性。

This thesis shows the sulphidation attacks of the different alloys of Cr-Ni-Fe at the point of temperature 600℃ with the 48mmHg of ps2; under this condition, these alloys have the high-temperatured attacks, mainly the sulphidation attacks. It produces layers of sulfuret with a little proportion of metals oxide in it. The results show that 1 ) The speed of the sulphidation attacks is at the lowest point when the proportion of carbon is only 0.3% in the alloy, as that done in the expeiment with the carbon proportion ranging from 0.15-0.45%. 2 ) The tesistance to sulfide tarni-shing is improved when Cr is added more into the alloy; 3 ) The RST is reduced when Ni is added more, and. 4 ) The RST is greatly improved when Al is put in, as there produces a mixture layer of A12O3 and OS which is a layer of fairly good protection.