The Basic Principles of High Temperature Vacuum Metallography

Lozinskii, M. G.

doi:10.1016/b978-0-08-009417-5.50007-9

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At 640 C (Figure 7) the curve has a distinct bend, repeating the "hot" hardness curve of M.G. Lozinski [35], indicating a qualitative change in strain resistance. The change of the hardness ramp is characteristic not only of iron but also of the other polymorphic metals (Co, La, Ce, Ti and Zr), which suggests, by analogy, a transformation in iron at about 650 C. М. Genzamer [18] determined σ0.2, σB, δ, ψ, σ -1 and HRC after isothermal transformation of austenite at 14 temperatures for steel with 0.78 %С but did not measure the hardness from 630 to 670 C. We investigated the effect of isothermal annealing between 580 and 680 C (Figure 8) on the hardness of carbon steels (U8 and 45) and pure iron (0.008 %C).…”

Section: Research Resultssupporting

confidence: 60%

630 ̊С±30 ̊С - Nodal (Critical) Temperature of Iron and Carbon Steel

Shakhnazarov

Pryakhin

Mikhailov

2021

MSF

View full text Add to dashboard Cite

The article deals with the problems of withstanding harsh temperatures by steel and iron. The authors of the work discuss iron denser high-temperature of γ modification and maximums and minimums of impact. In addition, the article analyses the transformations of iron and anomalies of properties: peak of heat capacity, acceleration of diffusion, etc. The authors take into account the consensus on the causes of polymorphism and the theoretical model of ferromagnetism. Besides, there is a consideration of "transformation" in interaction between Fe atoms that produce anomalies of steel properties. It is necessary to note the transformation detected by anomalies of any properties including mechanical. In the presented work the authors have made an attempt to prove transformations in iron at ~650 °C on the basis of extreme values of hardness and microhardness, metallographic structure, parameters of fine structure, precipitation resistance force depending on temperature. Therefore, the analysis of literature sources on physical and mechanical properties of iron and its derivatives has been made.

show abstract

Section: Research Resultssupporting

confidence: 60%

630 ̊С±30 ̊С - Nodal (Critical) Temperature of Iron and Carbon Steel

Shakhnazarov

Pryakhin

Mikhailov

2021

MSF

View full text Add to dashboard Cite

show abstract

“…This enhanced creep has an influence on the hardness derived from unloading curve analysis, which decreased from 2.3 GPa at 750 °C to 1.9 GPa at 950 °C. Due to the presence of an indentation size effect in tungsten the absolute values are higher than measurements at higher load in conventional hot hardness tests, 18,35 but after normalising to the room temperature values they are in reasonably good agreement. It was also found that an improved experimental design with a longer hold period at peak load improves the accuracy of elastic modulus measurements by allowing the sample to creep out more before unloading, as is recommended in ISO14577.…”

Section: Creep Of Thermally Aged Glass-ceramic Seal Materials At 25-7...mentioning

confidence: 76%

Extreme nanomechanics: vacuum nanoindentation and nanotribology to 950 °C

Harris

Beake

Armstrong

2015

Tribology - Materials, Surfaces & Interfaces

View full text Add to dashboard Cite

Elevated temperature mechanical and tribological properties can be more relevant for practical wear situations than corresponding measurements at room temperature. However, high-temperature nanomechanics and nanotribology are highly challenging experimentally. To overcome these challenges the NanoTest has been developed with active heating of the indenter and sample with resistive heaters, horizontal loading, patented thermal control method and stage design. By separately actively heating and controlling the temperatures of indenter and sample, their temperatures can be precisely matched so that there is no heat flow and minimal/no thermal drift during the high temperature indentation and measurements can be performed as reliably as at room temperature. Above 500 °C, it is beneficial to use a cubic Boron Nitride indenter with gas purging to limit oxidation of samples. To achieve higher temperatures without indenter or sample oxidation an ultra-low drift high-temperature vacuum nanomechanics/tribology system capable of testing to much higher temperatures has been recently developed (NanoTest Xtreme). The influence of time-dependent deformation on elevated temperature nanomechanical behaviour is discussed, using published results in Argon on glass-ceramic solid oxide fuel cell seal materials and previously unpublished nanoindentation measurements on single crystal silicon and polycrystalline tungsten using the NanoTest Xtreme in vacuum at temperatures up to 950 °C. Studies of the elevated temperature nano/microtribological behaviour of wear resistant nitride-based and MAX-phase coatings are also briefly reviewed.

show abstract

The Basic Principles of High Temperature Vacuum Metallography

Cited by 2 publications

References 0 publications

630 ̊С±30 ̊С - Nodal (Critical) Temperature of Iron and Carbon Steel

630 ̊С±30 ̊С - Nodal (Critical) Temperature of Iron and Carbon Steel

Extreme nanomechanics: vacuum nanoindentation and nanotribology to 950 °C

Contact Info

Product

Resources

About