Rolling-element fatigue life of AMS 5749 corrosion resistant, high temperature bearing steel

The rolling element fatigue lives of AMS 5749 and AISI M-50 were compared in tests run in the five ball fatigue tester and the rolling contact fatigue tester. The effects of double vacuum melting and retained austenite on the life of AMS 5749 were determined in five ball fatigue tests. The double vacuum melting process consisted of induction vacuum melting followed by vacuum arc remelting (VIM-VAR). In the five ball tests, VIM-VAR AMS 5749 gave lives at least six times that of VIM-VAR AISI M-50. Similar tests in the rolling contact fatigue tester showed no significant difference in the lives of the two materials. The rolling element fatigue life of VIM-VAR AMS 5749 was at least 14 times that of vacuum induction melted AMS 5749. A trend toward increased rolling element fatigue life with decreased retained austenite is apparent, but the confidence that all experimental differences are significant is not great

Effect of double vacuum melting and retained austenite on rolling-element fatigue life of AMS 5749 bearing steel

AMS 5749 steel combines the tempering, hot hardness, and hardness retention characteristics of AISI M-50 steel with the corrosion and oxidation resistance of AISI 440C stainless steel. The five-ball fatigue tester was used to evaluate the rolling-element fatigue life of AMS 5749. Double vacuum melting (vacuum induction melting plus vacuum arc remelting, VIM-VAR) produced AMS 5749 material with a rolling-element fatigue life at least 14 times that of vacuum induction melting alone. The VIM-VAR AMS 5749 steel balls gave lives from 6 to 12 times greater than VIM-VAR AISI M-50 steel balls. The highest level of retained austenite, 14.6 percent, was significantly detrimental to rolling-element fatigue life relative to the intermediate level of 11.1 percent

Towards an understanding of thermodynamic and kinetic controls on the formation of clay minerals from volcanic glass under various environmental conditions

lmogolite is the kinetically and thermodynamically favoured weathering product from rhyolitic volcanic glass in the soil-forming environment. However, on thermodynamic grounds imogolite would also appear to be the favoured alteration product of rhyolitic glass deposited in the nearshore marine environment. On the basis that the rate of conversion of glass to clay minerals is a function of the solubility of the clay mineral, smectite is expected to be formed under mildly diagenetic conditions, and formed more rapidly than imogolite in soil. The derived activation energies for formation of imogolite from glass in soils are appropriate for a diffusion controlled reaction, and appear consistent with the diffusion of the tetrahedrally co-ordinated species Al[iv](OH)₂(H2Q)⁺. In the marine environment, however the mechanism for all reactions appear to be surface reaction control

Apparatus for remote handling of materials

Apparatus for remote handling of materials are described. A closed housing is provided with first and second containers and first and second reservoirs for holding materials to be mixed. The materials are transferable from the reservoirs to the first container where they are mixed. The mixed materials are then conveyed from the first container to the second container preferably by dumping the mixed materials into a funnel positioned over the second container. The second container is then moved to a second position for analysis of the mixed materials. For example, the materials may be ignited and the flame analyzed. Access, such as a sight port, is provided in the housing at the analysis position. The device provides a simple and inexpensive apparatus for safely mixing a pyrophoric material and an oxidizer which together form a thermite type mixture that burns to produce a large quantity of heat and light

Wirtschaftswunder: A Study into the Causes and Catalysts of the German Economic Miracle

The purpose of this paper is to analyze the West German economy to find the reason for “Wirtschaftswunder,” the German economic miracle, and contrast the decisions made after WWII to those made after WWI. The approaches of foreign powers in these periods are also analyzed. After WWI, the subsequent hyperinflation and economic collapse is mainly found to be a result of poor economic decisions within German institutions, although the collapse was almost certainly supplemented by poor foreign policy decisions by the Allied Powers. Wirtschaftswunder was made possible by Ludwig Erhard’s reforms, which are found to have been much more important to West Germany’s success and successful denazification than the Marshall Plan. The best plan for economic recovery for Germany was one of least economic interference. In the years immediately following WWII, the Allied Powers were extremely influential in governmental institutions, but this was only to help stabilize the devastated country for a short period of time after the war and help rebuild its political institutions so it could return to self-governance. West Germany’s economy was allowed to grow, unhindered by large reparations payments, catching up to its productivity capacity that was never truly eliminated by Allied bombing during the war

Creative and emergent evolution and implications for religious education

Author has misnumbered the thesis, page 45 is not missing. Thesis (M.A.)--Boston Universit

Investigations of solid chemical barium release systems

Barium-copper oxide/canister barium vapor release system for geomagnetospheric measurement

Letter from Mrs. Mahalie R. Hodder, Brookline, Massachusetts, to Anne Whitney, Boston, Massachusetts, 1911 December 25

https://repository.wellesley.edu/whitney_correspondence/2637/thumbnail.jp

Letter from Mrs. Mahalie R. Hodder, Pass-a-Grille, Florida, to Anne Whitney, Boston, Massachusetts, 1914 February 26

https://repository.wellesley.edu/whitney_correspondence/2639/thumbnail.jp

Letter from Mrs. Mahalie R. Hodder, Brookline, Massachusetts, to Anne Whitney, Plymouth, Massachusetts, 1906 June 14

https://repository.wellesley.edu/whitney_correspondence/2635/thumbnail.jp