ラインパイプ用鋼の応力腐食割れ感受性に及ぼす環境因子の影響

概要

論文の詳細を見る
Stress corrosion cracking (SCC) susceptibility of X60 line pipe steel was evaluated by means of the slow strain rate technique (SSRT) as well as the static load technique (SLT) in four environments, i.e., NaOH, Na_2CO_3-NaHCO_3, Ca(NO_3)_2 and SO_2, that were found potentially to cause SCC by the potentiodynamic polarization screening tests on 25 chemical species present in the soil. The results obtained are summarized as follows : 1) SCC in NaOH could be produced at temperatures above 40℃, at stresses above 30kg/mm^2 and at potentials between -880 and -1230mV vs. Cu-CuSO_4. 2) SCC in Na_2CO_3-NaHCO_3 could be produced above 15℃, above 42 kg/mm^2 and between -650 and -875mV. 3) SCC in Ca(NO_3)_2 could be produced above 30℃, above 5kg/mm^2 and between +1120 and -480mV. 4) The minimum concentration required to produce SCC was 5% for NaOH and 0.5N for Na_2CO_3-NaHCO_3. 5) A saturated SO_2 solution was found to promote transgranular stress corrosion cracking in X60 line pipe steel at ambient temperature. 6) The SCC potential region indicated by SSRT in terms of reduction in area was in good agreement with that by SLT in terms of time to failure.
社団法人日本鉄鋼協会の論文
1983-09-01