Treat the tubes with cryogenics. It will increase the fatigue life considerably and has been found to improve the sound and playing characteristics. Yamaha offers cryo on some of their instruments, so it has been tested extensively.
The paper I noted states:
" In a Deep Cryogenic treatment the material is first allowed to cool from room temperature
to a temperature of -186 C by introducing the test piece in Liquid Nitrogen (LN2) controlled flow chamber up to 2-3
hours duration to take, then maintained in a cooling chamber...
Maui:
The scientific community generally accepts the beginning of the cryogenic temperature zone to be -244F, so the research you are criticizing was done well under cryogenic conditions. As a practical matter it takes a lot of liquid nitrogen to get a chamber down to -320F so a lot if not most...
Here is one. It was on the web and took about 3 minuets to find. I will submit it to the CSA database for inclusion.
International Journal of Engineering Research and Reviews ISSN 2348-697X (Online)
Vol. 2, Issue 4, pp: (18-23), Month: October - December 2014, Available at...
I've read your book. I have also bought it for my employees. Maybe you should take ASM Handbook Volume 4A off the shelf and read pages 382 to 386. I wrote that.
Brass, aluminum and plastics have no significant ferrite either, but show significant changes due to Deep Cryogenic Treatment. I will say again that many of the things happening at cryogenic treatments have nothing to do with retained austenite and martensite. That is the point! Many of the...
The idea that cryo treatment would do nothing is false. You are making your assumption that the only thing cryogenic treatment does is create an austenite to martensite transformation. This is a false assumption. If it were true, then cryogenic treatment would do nothing for brake rotors...
One way of relieving some of the residual stress would be to give the fasteners a true cryogenic treatment. This would also increase the fatigue life of the fastener.
Depending on the layout of your design, you can use vacuum insulation or aerogel. I suggest that you contact the Cryogenic Society of America and ask this same question. www.cryogenicsociety.org/ They can point you toward an expert.
Research on Deep Cryogenic Treatment (DCT)of materials in general is available at http://www.cryogenictreatmentdatabase.org/. This is site set up by the Cryogenic Society of America. I also suggest that you look in Volume 4A of ASM Handbook. There is an article there that differentiates...
Vacancies and other point defects are temperature dependent. Reduce the temperature and you reduce the vacancies, providing that you reduce the temperature slowly enough. This is why real DCT has very slow cool down rates. The equation that describes the number of point defects at equilibrium...
I can easily see where your shot peening company would come to their opinion, and on the face of it they are right. Shot peening is done to create a high compressive residual stress on and slightly below the surface. This raises the fatigue life because a crack cannot form in the compressive...
tbuelna:
I never said numerous papers were published by NASA. I said "places such as NASA." I quoted the papers conclusions. Release of residual stresses were significant. YOU stated that you doubted that there was any benefit for aluminum alloys. My claim was that there were effects on...
Tomwalz:
DCT will give consistent results if the parts treated are consistent. The variables are the components being treated and the processor being used. I cannot control the quality of what is sent for processing. Nor can any heat treater. But our processing machines are microprocessor...
First a word of disclosure. I own a cryogenic processing firm. I am co-chair of the ASM Cryogenic Committee. I have hosted ASM webinars in concert with a NASA engineer and a metallurgical engineer from Air Liquide. I think I can speak with authority on the subject.
The paper that tbuelna...
Interesting. People still believe the only thing Deep Cryogenic Treatment(DCT)can do is to convert retained austenite to martensite.
There are more than just "claims" that brake rotors last longer. There is proof that when they are properly DCT treated there is a substantial increase in...
A lot depends on how fast the temperature changed. With a slow drop in temperature several things will happen:
1. A slow drop in temperature will cause point defects out of the crystal structure. In the end there will be fewer vacancies in the matrix.
2. The solubility of the alloying...
NickE
Your statement that "properly heat treated 4130 or 4140 will not show significant property differences due to a post-heat treat cryogenic treatment" flies in the face of the research. Yes, hardness will change only a few HRC points and tensile strength will not change a whole lot, but the...
