R.S. DeFries

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R.R. MacFarlane

W.W. Dyrkacz

E E Reynolds

Mater Dei Hospital

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Mater Dei Hospital

University Hospitals Sussex NHS Foundation Trust

National Institute for Biological Standards and Control

Devon Energy (United States)

University of Michigan–Ann Arbor

British Orthopaedic Association

Faculty of 1000 (United Kingdom)

Robinson Brothers (United Kingdom)

Multiple Sclerosis Society

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The Elevated Temperature Properties of Two 81mm Mortar Tube Alloys 4337M and 4140

R.S. DeFries

Abstract : An evaluation was made of the effect of room and elevated temperatures (800 to 1200F) and times at these temperatures (0 to 30 hours) on the mechanical properties of two mortar tube alloys, AISI 4140 and AISI 4337 modified, quenched and tempered to four strength levels. The elevated temperature yield strength and ductility after exposure to the various temperatures for various times are discussed. The room temperature yield strength and -40F impact energy after exposure to various temperatures for various times are also discussed. Results of the elevated temperature tensile testing of the two alloys showed that the yield strength decreases rapidly with high temperatures. The ductility (%RA) increases with increasing temperature and remains fairly constant with time at temperature. The room temperature yield strength decreases with time after exposure at temperatures above the tempering temperature of the alloy. The -40F Charpy V-notch impact strength increases after exposure at temperatures higher than the tempering temperature of the alloy. Increasing the room temperature yield strength (by lowering the tempering temperature) does not significantly increase the elevated temperature yield strength of the alloy.

10.21236/ad0726952

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RESEARCH AND DEVELOPMENT OF WROUGHT AND CAST HIGH TEMPERATURE ALLOYS

R.R. MacFarlane R.S. DeFries

A study of wrought and cast Co-base and Fe-base alloys was conducted with the object of development of better high-temperature alloys having a minimum strategic alloy content. An alloy containing 10% Ni, 10% Cr, 10% W, 5% Mo, and 1% Nb + Ta was outstanding in rupture properties for the wrought Co-base alloys at 1500 to 1700 deg F. An 18% Mn, 12% Cr, 3% Mo, 0.8% V alloy had a good combination of properties for application at 1200 deg F for the wrought Febase alloys. Thermal shock properties were best for the cast alloys containing the highest Co. No correlation was apparent between thermal shock characteristics and other commonly measured properties. (auth)

Thermal shock

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RESEARCH AND DEVELOPMENT OF WROUGHT AND CAST HIGH TEMPERATURE ALLOYS. PROGRESS REPORT NO. 3 FOR SEPTEMBER 16, 1953 TO DECEMBER 15, 1953

R.R. MacFarlane R.S. DeFries E E Reynolds W.W. Dyrkacz

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DEVELOPMENT OF WROUGHT AND CAST ALLOYS FOR HIGH TEMPERATURE APPLICATIONS

R.R. MacFarlane R.S. DeFries

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The Estimation of Yield Strength from Hardness Measurements

R.S. DeFries

Abstract : Data are presented to show that the yield strength of gun steel and AISI 4340 alloy can be estimated from Rockwell hardness measurements. The expression, YS = 4.226(R sub c), where YS is the 0.1% offset yield strength in ksi and (R sub c) is the Rockwell C hardness of the material, was developed statistically to fit the data. It is shown that the yield strength within a gun tube forging can be estimated from the hardness measurements taken on a small flat area ground on the OD of the gun tube.

10.21236/ada016166

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CAST NICKEL-BASE HEAT-RESISTING ALLOYS. FINAL REPORT

R.S. DeFries E E Reynolds W.W. Dyrkacz

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Hydrostatic Extrusion of 60mm Mortar Tubes

R.S. DeFries

Abstract : Mortar tubes were successfully hydrostatically extruded from Inconel 718 proving the feasibility of the process. The yield strength of the 718 material was increased from 160 ksi to 240 ksi by the cold work induced by the extrusion process. A cost savings of about $400 per tube can be realized by hydrostatically extruding the mortar tubes close to finished size and thereby reducing the machining costs, rather than machining the tubes from forgings. Thus, it may be possible to economically use Inconel 718 and derive the benefits of the increased high temperature strength inherent in the material. As an adjunct to this project, an estimate was made of the potential savings for hydrostatically extruded gun steel mortar tubes compared to forged tubes. It is estimated that a savings of approximately $63 per tube would be possible.

Inconel

Hydrostatic equilibrium

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WROUGHT AND CAST HIGH TEMPERATURE ALLOYS. PROGRESS REPORT NO. 2 FOR JUNE 16, 1953 TO SEPTEMBER 15, 1953

R.R. MacFarlane R.S. DeFries E E Reynolds W.W. Dyrkacz

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