Showing papers by "William A.T. Clark published in 1986"
212 citations
TL;DR: The grain structure, inclusion content, and precipitate types were characterized for six heat treatments of a copper-bearing HSLA steel as discussed by the authors, where a higher austenitizing temperature combined with water-quenching resulted in an acicular ferrite microstructure, while lower temperatures produced equiaxed ferrite or ferrite-pearlite structures.
Abstract: The grain structure, inclusion content, and precipitate types were characterized for six heat treatments of a copper-bearing HSLA steel A higher austenitizing temperature combined with water-quenching resulted in an acicular ferrite microstructure, while lower temperatures produced equiaxed ferrite or ferrite-pearlite structures Refinement of equiaxed ferrite was observed in material austenitized at a high enough temperature to dissolve a portion of the carbonitrides, allowing reprecipitation during the austenite-ferrite transformation Age-hardening precipitated body-centered cubic copper clusters; face-centered cubic copper precipitates were observed in overaged material
48 citations
TL;DR: In this article, a partir d'experiences dans un microscope electronique en transmission is used to analyze the interaction entre un empilement de dislocations and un joint de grand angle.
33 citations
TL;DR: In this paper, the effect of nitrogen is incorporated into the thermodynamic model by means of the free energy interaction coefficients of nitrogen with chromium and carbon, and a mechanism by which nitrogen additions affect the sensitization kinetics of AISI 304 stainless steels is proposed.
24 citations
TL;DR: In this article, slow strain rate tests were conducted on solution annealed and sensitized AISI 304 stainless steels with varying nitrogen and carbon contents to study their susceptibility to stress corrosion cracking (SCC).
Abstract: Slow strain rate tests (SSRTs) were conducted on solution annealed and sensitized AISI 304 stainless steels (SSs) with varying nitrogen and carbon contents to study their susceptibility to stress corrosion cracking (SCC). The tests were conducted in deaerated 0.1 M Na2SO4 at 250 C at a strain rate of 2×10−6/s and an applied potential of 0 VH. For the sensitized SS containing 0.05 wt% carbon, susceptibility to intergranular stress corrosion cracking (IGSCC) decreased with nitrogen additions up to ∼ 0.16 wt%. Scanning electron microscopy (SEM) showed that a transition from IGSCC to transgranular stress corrosion cracking (TGSCC) occurred at greater nitrogen contents. Potentiodynamic polarization curves measured in the above environment were identical for both the solution annealed and sensitized conditions, but the latter showed slightly greater current densities (CDs). Nitrogen additions had no influence on anodic polarization characteristics. No changes were noted in the polarization curves, whic...
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TL;DR: In this paper, the electrical properties of both decorated and undecorated bicrystals were determined using a two-probe step I-V method, and the behavior of both types of bicystals compared.
Abstract: Silicon bicrystals have been fabricated by sintering together single crystal {001} and {111} wafers with low angle misorientations In the range of 0.5 to 3.0 degrees. The interfaces in these bicrystals contain regular arrays of screw dislocations with observed spacings of 10 to 40 nm. The dislocations were decorated with copper which was first sputter-deposited on an external surface, then diffused into the interface by annealing the bicrystal at 400°C for 15 minutes. Analytical electron microscopy was used to characterize the spacing, orientation, and copper concentration of these dislocation arrays. The electrical properties of both decorated and undecorated bicrystals were determined using a two-probe step I-V method, and the behavior of both types of bicrystals compared.
01 Aug 1986