ABSTRACTS OF LITERATURE
The articles listed below are from recent technical journals and may be of interest to members. Copies are available from Margaret O’Malley at IST Headquarters.
Wright, Roger N, Dr., Lawrenceville, USA "Tips From WireDrawing 101® - Wire Drawing Temperature -Part 4”, Wire & Cable Technology, September/October 2014, pp 32
In the first three columns of this series, we analyzed the overall increase in temperature during a wire drawing pass, with evaluations for the cases of steel, copper and aluminium drawing. It is quite useful to note that there are three sources of this heating, and that sophisticated heating control depends on an understanding of the relatiive contributions of these sources.
The drawing stress and work per unit volume involve contributions of uniform deformation, nonuniform or redundant deformation and friction. It is instructive to examine the contributions of each to the drawing temperature increase in the pass, acknowledging that all together, add up to overall equilibrated temperature increase in the pass.
(for Part 5 see below)
Bandini, M., Bologna, Italy "Peening - Almen Saturation Curve From A Statistical Perspective", MFN, Vol 15, September Issue, pp. 18-20
As widely known in the shot peening field, Intensity is an indirect measurement of the kinetic energy of the shot stream. It is a common opinion that the most accurate method of estimating peening intensity is to produce and analyze a saturation curve. Modern technology also enables direct measurement of the shot stream velocity. As a matter of fact, direct measurements of the average speed of the shot stream can be made by special instruments, but when it is necessary to know the effect of the stream on the real shape of the part being peened , the most accurate way still remains the saturation curve.
Balan, K., "The Future of Cleaning and Peening", The Shot Peener, Fall 2014, Volume 28, Issue 4, pp. 12-16
(..) THE NEXT QUANTUM LEAP
Let's start with blast cleaning. This process is utilized for (a) cleaning contaminants such as rust or scale for the purpose of a downstream coating process, and (b) removing heat treat scale off casting in foundries. We cannot do much with the latter except in terms of maintenance initiatives, but let us look at the former.
Cammet, J., "So You Think Almen Strip Coverage Is Important?", The Shot Peener, Fall 2014, Volume 28, Issue 4, pp. 18-20
YES, IT IS, but only in a limited sense. Almen strip coverage is important in that it must be uniform because that is an implicit and necessary condition to ensure that intensity determination via a saturation curve will be correct. Otherwise, Almen strip coverage is unimportant! One of the authors, John Cammet, has published articles on the general subject of coverage in the two previous issues of this publication. The first article, The Time Paradox in Peening, dealt with the separate issues of Almen strip exposure time for intensity determination and part exposure time in the peening process. The second article, Are you Peening Too Much?, dealt with the desirabilityof peening to lower coverage values than is conventionally practiced, that is, 80% coverage instead of 100%. While having no intention of writing a third article on the subject, the autors decided to address specifically the issue of Almen strip coverage and its relationship to part peening coverage.
Kirk, D., Dr., "Quantification of Shot Peening Coverage", The Shot Peener, Fall 2014, Volume 28, Issue 4, pp. 22-34
(..) A suggested identifying parameter for a shot stream's ability to achieve required coverage levels is described in some detail.
1 PARTICLE WORK CAPABILITY
Each effective shot particle has some capability for doing work on a component's surface. This capability depends upon the kinetic energy possessed by the particle. It is not commonly recognized that work units and kinetic energy units are identical, i.e.:
The units for work can be expressed as either N*m or kg*m2*s-2. (..)
De Moor, E and Miller, S. "Effects of niobium additions to a vanadium microalloyed high carbon wire steel", WIRE JOURNAL INTERNATIONAL, September 2014, pp. 69-72
Research shows that vanadium alloying can be used to increase strength levels of pearlitic high-carbon wire steels, predominantly through precipitation strengthening.
An increased demand for higher strength wire steels exists in a number of applications, driving further alloy development. Hypereutectoid carbon levels for increased strength are used in combination with silicon additions to prevent grain boundary proeuteuctoid cementite formation which can detrimentally affect drawability.
Wright, Roger N, Dr., Lawrenceville, USA "Tips From WireDrawing 101® - Wire Drawing Temperature -Part 5”, Wire & Cable Technology, November/December 2014, pp 44
These considerations [in part 4 (see above)] (..) resulted in some rather complex and unwieldy equations. In this column, we will insert some numbers and calculate some practical values with these equations.