These machines are capable of cleaning and descaling complex welded fabricated components and constructions. They are designed specifically to clean wide head and base plates, ribs, re-enforcements along with the welded seams after construction.
Chemical additives, or compounds, are one of the most essential elements of your mass finishing process and are the key to maintaining a stable, high quality mass finishing operation.
Compounds can help you achieve several tasks during your mass finishing process, including; degreasing, brightening, polishing, corrosion protection and stain resistance. One of their key functions though is keeping the process clean by continuously flushing out contaminants from your mass finishing system, such as, tiny metal particles from the work pieces or tiny media particles. This makes compounds indispensable tools for recycling your process water and ensuring an eco-friendly finishing operation. Here are four types of compounds that you need to know: Continue reading The Importance of Compounds
The key to having an efficient shot peening operation is the ability to control the parameters of the shot peening process, the Almen Test is one of the best ways to achieve this. The test consists of standardized test strips made from tool steel are mounted onto a special steel block and exposed to the blast stream over different time periods at a constant blast intensity which causes the strips to bend. The maximum arc height of the Almen strips provides a measurement of the degree of peening saturation, which is entered into a saturation curve. The saturation point is reached when a doubling of the blasting time increases the arc height by no more than 10%.
Almen strips are classified into 3 types:
“A” type is predominantly used for shot peening with cast shot or fully conditioned cut wire around shot.
“N” type are used mostly for glass bead peen and ceramic bead peen.
“C” type are used more rarely and are thicker than the other types.
Originally, the measurement system was developed and patented by John O. Almen in 1944. Modern shot peening evolved in the automotive industry most likely due to failures of engine valve springs which were prone to failure in service. General Motors superseded the design of the Almen gauge for use in the automotive industry, and has since been updated and modernised to ensure that the reading is taken from the central portion of the strip.
Rotary vibrators without inner dome – ideal for finishing work pieces
with complex shapes
Vibratory finishing systems are best known for treating a high volume of mass produced parts. However, thanks to a variety of new, innovative equipment designs, they are increasingly utilized for finishing single work pieces with highly complex geometries.
An example of one of these new equipment designs would be Rosler’s model R 150/2 DL, which is a rotary vibrator without an inner dome. In this unique finishing process the Continue reading Finishing work pieces with complex shapes
Shot peening is a special shot blasting process in which spherical blast media is thrown at the surface of metallic work pieces at high speeds and under highly controlled operating conditions. The impact energy of the pellets “cold forms” the upper layers of the metal similar to hammering and forging processes. The metal is alternately stretched and compacted causing a compressive stress in the upper surface layers. This offsets any inherent tensile stress as well as external tensile or compressive loads acting on the work piece. It increases fatigue strength and significantly reduces the risk of stress cracks. Depending on the components and the loads they are exposed to, shot peening can increase their fatigue life by up to 1,300%.
Drive components (i.e. gears) are often subjected to the shot peening process in order to induce compressive stress, which considerably reduces the risk of fatigue cracks during their operation. The service life of many components such as gearbox components, drive and crank shafts, springs, turbine blades and turbine components in general, can be significantly increased after going through a shot peening process.
Tip #4 – Optimum operating conditions
Once a mass finishing process has been established by the selection of machine, media and compound, the system must be constantly monitored and, of course, properly maintained. The good news is, this is quite easy! By following a few simple quality control rules, the process will remain absolutely stable, producing the desired finishing results for many years:
|Correct settings of the separation system||This helps keeping the times for separating the media from the finished work pieces at a minimum.|
|Undersize media removal||Undersize media must be removed from the system, as it can cause media lodging in the work pieces, clog up the machine drains and impair the finishing results.|
|Timely media replenishment||The media is subject to constant wear. In aggressive applications the wear rate can be 5 – 10%. Therefore, regularly adding media in to the machine is essential for the stability of the process.|
|Maintaining the optimum level of media in the machine||Too much media in the machine causes additional costs by unnecessarily increasing the media consumption. Not enough media in the machine will result in a poorer finishing quality and can cause nicking of the work pieces.|
|The correct dosing of compound||Too much compound can cause foaming problems, which unnecessarily increases costs. Not enough compound will impair the finishing results, causing work pieces to come out dirty and reduces media performance.|
|The correct dosing of water||Too much water will dilute the cleaning effect of the compound. Not enough water will impair the finishing results, causing the work pieces to come out dirty and reduces media performance.|
Tip #3 – The need for processing trials
Of course, the selection of the right machine, media and compound can sometimes be a bit intimidating. Not only does a mass finishing user have to choose among a wide variety of machine types and sizes, they must also pick the right media from hundreds of media types, shapes and sizes. And on top of all this Continue reading Tips to optimize your surface finishing process – Tip #3