Did you know that November 6 was National Stress Awareness Day? It seems an appropriate designation to cover the days and weeks that follow Election Day as well as those leading up to the holidays. For many who are well aware of the stress of the events of the season, Heat Treat Today wants to help with a different kind of stress relief.
Today we’re highlighting technical content that we’ve published over the last couple of years about stress relieving processes. Read an overview about stress relieving stainless steel components, listen to a Lunch & Learn dialogue about this underrated process, and explore a mechanical testing method for measuring material strength.
Stainless Corrosion
Stainless steel shines in our kitchens and is becoming more popular in auto showrooms, mostly because of the promise that it is corrosion resistant. What most people don’t realize is that stainless steel will rust in a lot of circumstances. Sarah Jordan explores how stainless steel can be compromised by improper heat treatment and the steps heat treaters can take to prevent corrosion:
“Improper heat treating can also contribute to stress corrosion cracking. When material is quenched, it can cause residual stresses that, if not relieved, can become an issue.
“Corrosion in stainless steel can often be traced to improper heat treatment. When stainless steel is heated between 842–1562°F (450–850°C), chromium carbides can form at the grain boundaries, depleting the surrounding areas of chromium and making them susceptible to corrosion.”
To read the article in full, click here.
Heat Treat Radio #88: Lunch & Learn — 3 Most Underrated Processes
In this Lunch & Learn episode from Heat Treat Radio, Dave Mouilleseaux discusses the three most underrated heat treat processes, including stress relieving manufactured components. If a comprehensive analysis of a heat treat operation needs to be performed on a manufactured component, such as a gear or a shaft, it is necessary to take into consideration any prior existing stresses in the part and what effect that has on the part.
Source: pixabay
“Many times during the course of my career, I’ve had a customer come to me and say, ‘The part I gave you was correct, and you’ve given it back to me and then fill-in-the-blank. It’s warped, it’s changed size, it’s shrunk, all of those things.’
“What have you done in your heat treating process?” asked Mouilleseaux. “You have to back up all the way to the beginning of how this part was manufactured and deal with all of those component steps in order to answer that question properly. Stress relieving is one of the answers. It’s not the answer. It’s not the only answer, but it is one of them that has to be considered.”
To listen to this episode of Lunch & Learn, click here.
Indentation Plastometry
Source: Plastometrex
Mechanical testing is a standard production step in heat treating operations, but conventional methods of testing don’t always yield stress values consistent with the testing calculations.
Indentation plastometry allows users to obtain material strength characteristics in a way that is faster, cheaper, and simpler than conventional mechanical testing procedures. James Dean explores this novel mechanical testing method developed to infuse efficiency and accuracy into the process.
“The testing process is fully automated and involves three simple steps. The first is the creation of an indent using the indentation plastometer which is a custom-built, macromechanical test machine. The second is measurement of the residual profile shape using an integrated stylus profilometer.
“The third is the analysis of the profile shape in a proprietary software package called SEMPID, which converts the indentation test data into stress-strain curves that are comparable to those that would be measured using conventional mechanical testing methods. The entire procedure takes just a few minutes, and the surface preparation requirements are minimal.”
To read this article in full, click here.
