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HY-80 steel is a real bear to work with. As previously mention,
pre-heat and post-heat are a real issue. We had to have the torpedo loading
skid mounting holes filled and redrilled due to an issue. VERY HOT heating
pads were placed in the area to bring up the temperature in preparation for the
welding and then had to be left on for a long time afterwards. The temperature
also had to be stepped down as part of the post-heat also if I remember
correctly. HY-80 is very susceptible to cracking; our hulls had to have continuous
NDT to insure their integrity. Any potential issues had to be ground and weld
filled. Besides, it is very expensive if you can procure it, very difficult to
work, and a pain to maintain. There are a lot of other choices I would make
for hull material before HY-80. Respectfully, Jay K. Jeffries Andros Is., Natura nihil fit in frustra - Nature does nothing in vain -----Original Message----- As someone who welds on submarines for a living, I'd have to agree with Dan H's methodology for welding the rings. It is a good way to minimize the stress. With regard to what it's imperative that anyone even considering building any sort of pressure vessel knows these things. Understanding the stress that welding causes on steel is VERY important to know, especially when your life is being supported by it. While there are a few methods of stress reduction, not all are readily available to all PSubbers. The best idea, if you haven't spent any time welding professionally, or even if you have, is to read over some corporate welding requirements. Anything you can get your hands on. A lot of them specify pre-heat and interpass temperatures, joint design specifications, and many other things. I think the American Bureau of Shipping documentation on Hyberbaric Chambers has a lot of these things in there as well. If you have the time, sit in on a metallurgy class at a local college. Or attend as a student. If you're welding yourself, there are SO MANY things you can and should learn before tackling such a project. One question I have for Has anyone constructed a K-350 submarine out of HY-80 steel or any other material? Would that increase it's depth capacity? What do the plans specify? Thanks, -Tom On 9/10/06, ShellyDalg@aol.com <ShellyDalg@aol.com> wrote: > > > Hello. One more thing. I asked the question about stress relieving
the > finished hull also. There are some companies that have huge ovens
to do just > that. One in > for high pressure, and will even do a whole tank. > Their oven is very large. I think stress relieving is required on
tanks that > store very cold things and create problems with cold brittle
stress. > The company is " Fort Worth F & D Tank Head " --great
prices there. > Frank Dalgleish. ************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. If you want to be removed from this mailing list simply click on the link below or send a blank email message to: removeme- Removal of your email address from this mailing list occurs by an automated process and should be complete within five minutes of our server receiving your request. PSUBS.ORG 603-529-1100 ************************************************************************ ************************************************************************ ************************************************************************ |