Deformation and Fracture of Oxides Fabricated on 304L Stainless Steel via Pulsed Laser Irradiation

2012 ◽  
Vol 1424 ◽  
Author(s):  
Samantha K. Lawrence ◽  
Douglas D. Stauffer ◽  
Ryan C. Major ◽  
David P. Adams ◽  
William W. Gerberich ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Electrical Contact ◽  
Constant Load ◽  
Laser Exposure ◽  
Ambient Atmosphere ◽  
304L Stainless Steel ◽  
X Ray Diffraction ◽  
Electrical Contact Resistance ◽  
Deformation And Fracture ◽  
Unique Approach

ABSTRACTLocalized heating of metals and alloys using a focused laser beam in ambient atmosphere produces dielectric oxide layers that have characteristic optical appearances including different colors. Nanoindentation probed the deformation and fracture of laser-fabricated oxides on 304L stainless steel. Conductive nanoindentation measured electrical contact resistance (ECR) of the same colored oxides indicating a correlation between laser exposure, conductance during loading, current-voltage (I-V) behavior at constant load, and indentation response. Microscopy and X-ray diffraction examined the microstructure and chemical composition of the oxides. Combining techniques provides a unique approach for correlating mechanical behavior and the resulting performance of the films in conditions that cause wear.

Fabrication of Metal Matrix Composites Based on Stainless Steel Having Low Electrical Contact Resistance by Powder Metallurgy

2019 ◽  
Vol 25 (1) ◽  
pp. 1755-1763
Author(s):  
Joon-Hwan Choi ◽  
Jong-Jin Choi ◽  
Jungho Ryu ◽  
Byung-Dong Hahn ◽  
Woon-Ha Yoon ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Powder Metallurgy ◽  
Contact Resistance ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Electrical Contact ◽  
Matrix Composites ◽  
Electrical Contact Resistance

Stick-Slip\Smooth Slip as a Function of Ambient Gases and Pressures Disproving Previous Models of Adhesive Wear

1988 ◽  
Vol 140 ◽  
Author(s):  
Chao Gao ◽  
Doris Kuhlmann-Wilsdorf ◽  
David D. Makel
Keyword(s):  
Film Formation ◽  
Surface Film ◽  
Substrate Surface ◽  
Electrical Contact ◽  
Copper Substrate ◽  
Ambient Atmosphere ◽  
Surface Films ◽  
Electrical Contact Resistance ◽  
Stick Slip ◽  
Average Value

AbstractFive different slip modes have been identified for bundles of copper fiberssliding on a smooth copper substrate in atmospheric air, argon and nitrogenat pressures from atmospheric to 0.01 Torr. These are stick-slip, variable sliding, intermittent stick sliding and two kinds of smooth sliding, one apparently a basic property of clean surfaces and the other due to contaminants. These forms of sliding are rather persistent once established, and they follow some trends. Specifically, low-pressure smooth sliding is coordinated with a value of the coefficient of friction (μ) near 0.15 and is seen when the surface film is exceptionally thin, while intermittent stick sliding appears to be due to “pads” on the substrate surface,and variable sliding to small particles caught in between the fibers and the copper substrate. However, the five slip modes are erratic in that under the same conditions one or another or yet a third may be observed, even though the electrical contact resistance (R) depends rather reproducibly on time, load, velocity, ambient atmosphere and pressure. That dependence indicates an equilibrium between film destruction through sliding and film formation, overwhelmingly through the presence of oxygen. In the stick-slip mode the difference between pst tic and ųK itic appears to be roughly proportional to ų 0.15, i.e. tfiee xcess of e average value of the friction coefficient above 0.15, being about 20% for ų 0.3 andvanishing near ų =0.15. During slip episodes, R spikes roughly in proportion to their magnitude. Some tentative interpretations are offered, based on the concept that ų consists of three additive components, namely due to the bulk (ųBulk), due to debris (ųDebris), and dueto scoring of surface films (ųFilm).At any rate, the conclusion that the results contradict all previous models of “adhesive” wearis inescapable.

scholarly journals Determination of phases and residual stresses after martensitic transformation induced by rolling in 304L stainless steel

2019 ◽  
Vol 24 (3) ◽  
Author(s):  
Juciane Maria Alves ◽  
Luiz Paulo Brandao ◽  
Andersan dos Santos Paula
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Martensitic Transformation ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Sample Thickness ◽  
304L Stainless Steel ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACT The 304L austenitic stainless steel is susceptible to deformation induced martensitic transformation. This phase transformation depends on the temperature as well as on the mode, rate and level of deformation. In this work the phases and residual stresses of a 304L TRIP steel where martensitic transformation was induced by cold rolling were investigated by X-ray diffraction XRD. The analyses were performed for different sample thicknesses. The results showed that the phase composition and the residual stresses are strongly dependent on sample thickness. All samples showed a compressive residual stress.

Oxidation of 304L Stainless Steel by Steam and by Air

CORROSION ◽  
1969 ◽  
Vol 25 (1) ◽  
pp. 7-14 ◽  
Author(s):  
J. T. BITTEL ◽  
L. H. SJODAHL ◽  
J. F. WHITE
Keyword(s):  
Stainless Steel ◽  
Reaction Rate Constant ◽  
304L Stainless Steel ◽  
X Ray Diffraction ◽  
Oxide Interface ◽  
Spinel Layer ◽  
Temperature Range ◽  
Loss Of Coolant Accident ◽  
Rate Behavior ◽  
Parabolic Rate

Abstract The oxidation of 304L stainless steel has been measured in steam and in air in the temperature range from 1000 to 1375 C (1832 to 2507 F) using a thermogravimetric technique. This temperature range is of interest in the analysis of a reactor loss-of-coolant accident. Experiments in steam showed initial linear weight gain with time for the first 6 to 28 minutes, followed by parabolic rate behavior. The linear reaction rate constant W/t was found to be 1.1 × 105 exp (−44,350/RT) while the parabolic constant W2/t was found to be 2.4 × 101 2 exp (−84,300/RT), where T is in °K and W is in mg/cm2 and t is in sec. The parabolic rate controlling process is diffusion through an Fe-Ni-Cr spinel layer observed in the inner layer of the scale. The oxidation of 304L stainless steel by air from 1100 to 1360 C (2012 to 2480 F) was slow compared to the oxidation by steam in this same temperature range, parabolic rates being lower than those in steam by a factor of ~ 103. Although X-ray diffraction observed Fe3O4 (major) and Fe2O3 (minor) on the surface of the coatings formed in air at temperatures of 1360 C and below, Cr2O3 was found at the metal-oxide interface. The low rates in air thus reflect the formation of a protective Cr2O3 film. The rate in air at 1375 C is exceptionally rapid compared to those at the lower temperatures possibly because of the Fe-FeO liquidus at 1370 C (2498 F).

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