Let us begin from where we left in the previous blog. Gray Iron Sanding casting exhibits low level of elongation values that leads to large amount of stress on the casting that is poorly designed.
How can stress be measured?
There is only a sure-fire method of determining stress levels in a casting under load and that is achieved by using SR-4 strain gages.
If there is no proper stress analysis, what the casting manufacturers do is beef up the section in which failure is observed. This approach does not lead them to the best design, and, as a matter of fact, may worsen the condition. It is vital to proper design castings with the right fillets, radii and thickness.
Gray Iron castings are made use of in a spectrum of different applications and industries. For example, Grey Iron also has a good track performance in an internal combustion engine.
Another common application of Gray Iron castings involved sliding surfaces including cylinder bores, machine tool ways and piston rings. There are many reasons attributed to this behaviour including oil retention in the graphite area and lubricating effect of the graphite flakes. This is pretty much true, but it’s also likely that the graphite flakes allow some negligible accommodation of the pearlite matrix at contact areas between mating surfaces. It is not quite often that you derive perfect fits, and commonly high spots in mating metal surfaces may lead to high unit pressures resulting in seizing.