Experimental Research on Hydrogen Resistance Performance of Different Microstructure

Abstract

The paper studies the effects of different microstructures on the hydrogen resistance properties. Four kinds of microstructures were obtained by using four kinds of heat treatment processes for 45 steel materials. The mechanical properties of different microstructure materials were obtained by Vickers hardness test and internal residual stress test. The relationships between hardness and depth of four kinds of microstructures were obtained by stratified microhardness test. Static hydrogen resistance property of different microstructures was obtained by using the stripping method. Results show that the H2S corrosion layer of different microstructures is basically the same, and the depth and hardness distribution of the hydrogen embrittlement layer are quite different. More pearlite, lead to the weakness of hydrogen resistance property; quenched and tempered sorbite after the hydrogen corrosion is better than ferrite + pearlite structure, martensite has a good resistance to hydrogen permeability. Finally, the relationships between microhardness and depth of the hydrogen embrittlement layer with different microstructures were fitted.

Effect of Microstructure on the Corrosion Fatigue Crack Growth of Low and Medium Steels

“…In the three heat treatment states, the quenched and tempered state showed the best corrosion fatigue resistance. Based on the literature research [13], we think there are two reasons for this result. In terms of corrosion resistance, tempered ne pearlite has the best corrosion resistance among the three microstructures.…”

“…In the low ΔK region, owing to the low strain rate around the crack tip, the corrosion factor dominates the crack propagation. Li and Wang [13] studied the static hydrogen resistance of 45 steel with di erent microstructures by layer-by-layer micro-hardness method with thickness of hydrogen embrittlement a ected layer and hydrogen induced hardness increment (ΔHV) as parameters. eir main ndings are shown in Figures 7 and 8.…”