HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  RESOURCE CENTER  |  INDUSTRIES
REGISTER   |   LOGIN   |   HELP
naperlou
User Rank
Blogger
Process cost
naperlou   8/6/2012 9:09:18 AM
NO RATINGS
This is an interesting example of a failure mode that is not going to be easy to predict.  It seems that, short of testing a sample of the parts after each process, one can only track the parts after production and remedy situations as they occur.  This requires a detailed tracking of the products after delivery and detailed reports of problems.  In general, quality control systems do this.  By linking those databases with design data in a PLM system, another big theme of Design News lately, one can avoid the problem in the future. 

TJ McDermott
User Rank
Blogger
Re: Process cost
TJ McDermott   8/6/2012 10:11:28 AM
NO RATINGS
Alternatively, it might mean derating the usable strength of the parts in order to eliminate the process cost.

tekochip
User Rank
Platinum
Great Story
tekochip   8/6/2012 10:44:58 AM
NO RATINGS
Great story, that's an obscure and dangerous failure mode.


Dave Palmer
User Rank
Platinum
Re: Process cost
Dave Palmer   8/6/2012 11:50:08 AM
NO RATINGS
@TJ McDermott: I would strongly recommend against derating hydrogen embrittled parts, if by derating you mean using the affected parts in a lower-stress application.  The problem is that it's extremely difficult to predict what level of stress a hydrogen-embrittled part will fail at.  Even residual stresses from the forming process may be enough to produce microcracks, which may propagate later in fatigue.  If I knew that a part was likely to be hydrogen embrittled, I wouldn't recommend using it in any application.

The same line of argument applies to baking parts as a re-work method after a problem has been found.  As I mentioned, it's important to bake parts as soon as possible after plating or welding.  Some aerospace specifications require that this be done within one hour.  The more time passes, the less effective baking will be.  This is not so much due to the hydrogen being any more difficult to remove (although you will hear this claim), so much as the fact that microcracks may have already formed as a result of residual stress.  Obviously, once cracks have formed, no amount of baking will heal them.

As naperlou pointed out, prevention of process-induced hydrogen embrittlement depends on having a good quality system in place.  If you're plating or welding high-strength parts, you need to ensure that they are always baked at the proper temperature within the specified length of time.

bdcst
User Rank
Platinum
Re: Process cost
bdcst   8/10/2012 12:17:43 PM
NO RATINGS
Well, hydrogen embrittlement is  a long known issue that has played havoc with metals at nuclear power plants and has lead to fuel rod cadding failures along with reduction of the rating of some containment vessels.



Partner Zone
Latest Analysis
With LEDs dropping in price virtually every year, automakers have begun employing them, not only on luxury vehicles, but on entry-level models, as well.
The 3D printing revolution seems to have a knack for quickly moving technology ahead by way of collaborative effort and even a little friendly competition -- all of course in the name of scientific advancement.
Littelfuse Inc. has created a NASA Exploration & Discovery Experience for the engineering community as part of its 2013 Speed2Design promotion.
Advantech has launched a new series of motion-control I/O modules to meet the increased demands that come with more distributed industrial systems that require control of a growing number of axes and devices.
Using almost 200 light-emitting diodes in the front and back of the new 2014 CTS, Cadillac designers are showing how LEDs can change the character of a vehicle.
More:Blogs|News
Design News Webinar Series
5/22/2013 9:00 a.m. California / 12:00 p.m. New York / 5:00 p.m. London
5/15/2013 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
5/29/2013 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
5/30/2013 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
Blogs from Our Sponsors
From Dell / Intel®
New Paradigms in Design Work
Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013    3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
From Dell / Intel®
Increased Workstation Performance Is as Easy as 'DPPO'
Trey Morton, Dell, 4/25/2013    2
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
From Dell / Intel®
Taking Some of the Grit out of Manufacturing
Kirsten Billhardt, Manufacturing Industry Marketing Strategist, Dell, 3/26/2013    5
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
May 20 - 24, Automation Technologies & Trends for Smarter Homes & Buildings
SEMESTERS: 1  |  2  |  3


DN Radio
Sponsored by
NEXT UPCOMING BROADCAST
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2013 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service