The high- and low-cycle fatigue behavior of Ni-contain steels and Ni-alloys in high pressure hydrogen

The effect hydrogen on short-term strength and plasticity, high- and low-cycle durability of 15Cr12Ni2MoNMoWNb martensitic steel, 10Cr15Ni27Ti3W2BMo austenitic dispersion-hardened steel, 04Kh16Ni56Nb5Mo5TiAl and 05Kh19Ni55Nb2Mo9Al Ni-base superalloys in range of pressures 0–30 MPa and temperatures 293–1073 K was investigated. In the case of 15Cr12Ni2MoNMoWNb steel and 04Kh16Ni56Nb5Mo5TiAl alloy the dependence of low-cycle durability (N) and characteristics of plasticity (δ and ψ) on the hydrogen pressure consists of two regions. In the first region (low pressures), the N, δ and ψ abruptly drops, and in the second, the negative action of hydrogen becomes stable or decrease negligibility. This means that there exists a pressure under which the degradation of this material with hydrogen reaches its limit. The additional effect of preliminary dissolved hydrogen on the properties of 15Cr12Ni2MoNMoWNb steel and 04Kh16Ni56Nb5Mo5TiAl alloy developed at hydrogen environment pressure least of 10 MPa. In the case of 10Cr15Ni27Ti3W2BMo steel and 05Kh19Ni55Nb2Mo9Al alloy the low-cycle durability N, characteristics plasticity δ and ψ decrease in whole hydrogen pressure range. Preliminary dissolved hydrogen leads to a considerable additional decrease in the properties of this alloy.

► Martensitic and austenitic steels and nickel alloys in gaseous hydrogen. ► Embrittlement increase with strain amplitude decrease. ► Temperature range of essential degradation is a structure-sensitive factor.