AWS D1.1 to qualify HY-100 to itself

By Kix

Date 03-03-2009 18:23

You meet the intentions of sec 4 by do exactly that "meeting the intentions and instructions of sec 4". Whether or not the parts of your procedure that you told us about will work are tuff to say because you didn't really go into a lot of detail about the process, cooling rate, joint detail, etc etc. It sounds like you are on the right track so now you must test your procedure and see if it meets sec 4 requirements. You can pretty much do whatever you want, like covering with a fire blanket for a certain time or preheat to a certain temp as long as it's in the WPS. You just have to prove your recipe.

By bozaktwo1 (***)

Date 03-22-2009 22:42

HY100 is easy to weld, as long as you maintain that preheat/interpass temp. The reason NAVSEA requires certain tests is that the HY80/100/120 grades were used extensively in submarine hulls. The procedures used in welding those boats have to be rock solid, as usually over 100 guys' lives depend upon it.

By ssbn727 (*****)

Date 04-12-2009 18:34

If you would permit me to add to your excellent response Bozaktwo1, I wholeheartedly agree with everything you said with respect to HY steels used in submarine hulls as I personally have a wee bit of experience with them (Helped construct in some way or another 14 688-Los Angeles class, and the first four Trident-Ohio class "Super-Boomers" SSBN's, otherwise known as FBM's also). I also helped maintain a few of the older boats which for quite a few of them have met their fate after some thirty years of service in the scrap heap out near San Francisco's Mare Island complex where eventually some of the metals are recycled to be used in constructing new "boats."

The only thing that I question, and it really may be nothing to worry about except for the fact that for that thickness of .750", I would slightly increase the preheat temp to 200 degrees F, and maintain an interpass temp of 300 F max. as you mentioned earlier. I mean 125 degrees F is a good starting point but, as soon as the thickness of HY steels extend beyond .500" the safe bet is a least 200 degrees F in order to insure that ther is no "HIC, or HAC" (Hydrogen Induced Cracking, or Hydrogen assisted Cracking). Just another "Bubblehead" giving his two cents worth!!! ;) ;) ;)

Respectfully,
Henry

By bozaktwo1 (***)

Date 04-13-2009 16:56

Henry,

Coming from you that is a real compliment. Thank you, and I hope that the powers that be see fit to allow you to grace us with your presence a little more often here, so you can continue to give this fresh-air snipe that two cents' worth! :)

By petty4345 (**)

Date 04-14-2009 13:08

Henry,
I was hoping that you would chime in on this one, as I have read a lot of your posts and know that you have extensive experience with this material.
As I stated in my original post, I understand the importance of the additional extensive testing required by section 16 of Tech. Pub 1688 because of the materials use in fabrication of pressure hulls and with my part being a fixture required to be welded in accordance with AWS D1.1 per the customer drawing, I tried to follow what I thought made sense from section 16 for my application.

What worries me a little is the fact that someone could take on a job like this with no knowledge of the HY-100 material or even being aware that there are guidelines in 1688 drawn from extensive research by the Navy that could help one to make smart decissions developing a weld procedure and producing a safe part.
I'm no expert on anything, but I probably could have done a lot less and met the AWS requirements.
And maybe my part would have been ok, maybe not.

By 803056

Date 04-15-2009 12:29

You are on the right track by reading NAVSEA welding standards for some useful insight on welding the HY-80 and HY-100 materials. Information on issues such as preheat, heat input limitations, conditioning the filler metals, etc. can be gleaned from the military welding standards. Use that information to formulate your preliminary WPS and qualify it as required by Clause 4 of AWS D1.1 if that is what your client is requesting you to do.

You don't have to be a welding engineer to be a designer. Most designers give minimal consideration to the weldability or the inspectability aspects of their designs. Welding and inspection is often left to the fabricator to deal with.

Best regards - Al