Hydrogen In Specimens Research Articles

The Metallurgical hydrogen as an indicator and cause of damage to rolled steel: Hydrogen diagnostics of fracture

Fatigue tests and measurements of the volumetric distribution of metallurgical hydrogen in specimens cut from rolled I-beam 60Sh3 made of steel 10KhSND were carried out. Fatigue tests show a 20% reduction in fatigue limits compared to similar sheet material. On the fractures of the samples, there are flock-like defects in the areas of interface of the flanges of the I-beam, or the so-called zones of difficult deformation. The concentration of metallurgical hydrogen is unevenly distributed and varies from 0.17 ppm to 1.8 ppm. Large concentrations of hydrogen are observed in the zones of difficult deformation, which indicates the hydrogen nature of the metal defects observed at the fracture. The result of mechanical tests and hydrogen diagnostics is a manufacturing defect of rolled products that cannot be corrected. Hydrogen diagnostics using metallurgical hydrogen (without hydrogen charging samples) takes tens of times less time than mechanical tests, and gives an adequate result.

Effects of hydrogen on passive film and corrosion of aisi 310 stainless steel

The effects of hydrogen in AISI 310 stainless steel on pitting were investigated in a borate buffer solution (pH 8.5). The pitting susceptibility was strongly influenced by the hydrogen in the alloy and was correlated with the semiconductive properties of the passive film. Hydrogen in specimens caused a p–n inversion for the film.

Comparison of the Behavior of Hydrogen in Two Carbon Steels Differing in Sulfur Content

Abstract The role of sulfide inclusions in hydrogen diffusion and trapping in two steels with different contents of sulfur (0.003 and 0,024%S) was examined. The content of hydrogen in specimens aft...

鋼の水素脆化に関する研究(第1報)

The discontinuity-migration theory on hydrogen brittleness of steels has been published and supported by researchers. The purpose of this investigation is to reconsider this theory on hydrogen brittleness and, if possible, to establish the new theory.In this paper, authors report the results of a few experiments on hydrogen brittleness of mild steel. Hydrogen was charged in mild steel specimens by cathodic electrolysis method (5%H2SO4, 0.08-0.09A/cm2, carbon tube anode used). The volumes of hydrogen in specimens were regulated with change the charging hours and were measured using other specimens before mechanical tests.On mechanical tests, tensile test, V-notched slow bend test and V-notched charpy impact test were used.(1) In the case that the specimens were tested soon after charging; Yield strengths and maximum stresses on tensile test were almost same value, in spite that the volumes of hydrogen in specimens were different.But the elongation was remarkably decrease in accordance with increase of the volume of hydrogen in specimen.Energy of crack initiation and propagation on V-notched slow bend test were also remarkably decrease. The decrease of ductility on V-notched charpy impact test with increase the hydrogen in specimen was considerably remarkable, in spite that the test was carried out under very high speed and atomic hydrogen in specimen could not consider to migrate through the gap of Fe-atom.(2) In the case that specimens were aged up 4 days after charging before test; Ductility was remarkably recovered nearly equal to that of virgin specimen.From these experimental results and consideration, authors obtain the guiding-star of the new theory of hydrogen brittleness.