Short-range ordering and mechanical properties of a Ni-20%Cr alloy

The mechanical behavior of a coarse-grained (100 mm) nickel-base alloy nichrome (Ni-20%Cr) was studied in compression at temperatures ranging from 150 to 1000°C. It was shown that in the temperature interval of 300-600°C this alloy demonstrates the following features of mechanical behavior: i) positive temperature dependence of yield stress; ii) jerky flow associated with the Portevin-Le Chatelier (PLC) effect ; 3) very high value (115 MPa) of “threshold” stress at 650°C. These features of mechanical behavior can be related to short- range ordering (SRO). It was shown by differential scanning calorimetry that SRO takes place in this temperature range, causing PLC effect and positive temperature dependence of yield stress. In addition, SRO has persistency effect on yield stress and creep resistanceyesBelgorod State Universit

Creep and Deformation of Metals and Alloys at Elevated Temperatures

Various aspects of creep and deformation Creep resistance is an extremely important characteristic to be evaluated for structural materials that are used, for example, in aircraft gas turbines, fossil power plants, nuclear reactors, etc.behaviors of metals and alloys at elevated temperatures are of great interest to materials scientist

On the origin of the superior long-term creep resistance of a 10% Cr steel

A low-nitrogen 10% Cr martensitic steel containing 3% Co and 0.008% B was shown to exhibit an extremely long creep rupture time of ∼4·104 h under an applied stress of 120 MPa at 650 °C. The creep behavior and evolution of lath martensite structure and precipitates during creep at these conditions were studied. The main feature of the microstructure under long-term creep is retention of the lath structure until ruptur

Effect of the strain rate on the low cycle fatigue behavior of a 10Cr-2W-Mo-3Co-NbV steel at room temperature

The effect of a strain rate varying from ̴10-3 to ̴10¯⁵ s¯¹ at a strain amplitude ranging from ±0.25% to ±0.6% on the low cycle fatigue (LCF) behavior and the microstructure of a 10%Cr-2%W0.7%Mo-3%Co-NbV steel with 0.008 wt.

Effect of short-term aging on the impact toughness of advanced 10% CR steel

Heat-resistant high-chromium martensitic steels are widely used in various critical components of fossil power plants due to their superior creep resistance and high-temperature strengt

Impact toughness of a 10% Cr steel with high boron and low nitrogen

The effect of temperature on the impact toughness and fracture behavior of a 10% Cr-2% W-0.7% Mo-3% Co-0.05% Nb-0.2% V-0.008% B-0.003% N (all in wt%) steel was studied. The ductile-brittle transition (DBT) occurs at 10 °C. At the DBT temperature (DBTT), the onset of unstable crack propagation occurs at the maximum load. The mbrittlement is attributed to the onset of unstable crack propagation at stresses below the general yieldin

Strain-induced Z-phase formation in a 9% Cr-3% Co martensitic steel during creep at elevated temperature

The size and distribution of Cr(V,Nb)N (Z-phase) particles in a 9Cr-3Co-2W-0.6Mo-0.1Ni-0.2V-0.06Nb-0.1C-0.05N-0.005B steel subjected to creep rupture test during 11,151 h at 650 °C under an applied stress of 100 MPa were studied. The replacement of V-rich (V,Nb)(C,N) carbonitrides by Z-phase was accelerated by plastic flow as suggested by a comparative analysis of these particles in different portions of crept specimen, namely, the grip section, the portion of uniform elongation, and the necked portion

On effect of rhenium on mechanical properties of a high-Cr creepresistant steel

Addition of 0.2% rhenium in the experimental steel improved the short-term creep strength at 650 C. Comparison of kinetics of tungsten depletion from the matrix in different high-Cr martensitic steels showed that rhenium in the experimental 10Cr-3Co-3W-0.2Re steel did not lead to retaining an increased amount of solute W in the ferritic matrix during both aging and creep at 650 C. At the same time, the precipitation of the high fraction of the fine Laves phase particles provided the effective particle strengthenin