ATI 425® Titanium Alloy
I N T R O D U C T I O N
ATI 425® titanium is an innovative high strength alloy that has strength comparable to Ti-6-4, yet has the advantage that it can be cold worked. Originally developed for armor plate for ballistic protection, it was observed during processing to have exceptional hot workability. This observation led to additional testing that eventually demonstrated the alloy's versatility. ATI 425® titanium is produced by ATI Wah Chang and ATI Allegheny Ludlum in a variety of forms, including sheet, coil, strip, Precision Rolled Strip® product, plate, seamless tube and pipe as well as cast and engineering products.
ATI 425® titanium is an alpha-beta alloy that utilizes iron in place of some higher-cost vanadium as a beta stabilizer. Among its advantages is that even though it is classified as a high-strength alloy, it can be cold worked quite easily, compared with Ti-6-4 which is unworkable at cold temperatures. Cold rolled — annealed ATI 425® titanium sheet has been bent to radii 2.5T at 105° included angle. This ductility may lead to much easier fabrication.
C E R T I F I C A T I O N S
ATI 425® titanium is recognized by ASTM and has been assigned grade 38. The ASME Board on Pressure Technology Codes and Standards (BPTCS) has approved ATI 425™ titanium for use in Section VIII, Div. 1 construction up to 600°F (316°C). ATI 425® titanium can be welded using ERTi-38 weld wire, which is producedin accordance with AWS 5.16/A5.16M (pending approval).
SPF
Recent testing by Battelle (Technical report Characterization of Titanium ATI 425® Alloy Sheet under SPF Conditions indicates that ATI 425® titanium is also Super Plastic Formable at conditions that are commercially viable (830°C - 900°C, strain rate = 3 x 10-4/sec). Its performance under these conditions is very similar to Ti-6-4 SPF grade sheet.
F O R M A B I L I T Y
ATI 425® titanium can be both hot and cold worked. Mill annealed, cold-rolled sheet can be bent to radii down to 2.5T in thickness of 0.100 in. and under. Light plate, nominal 0.25 in. and 0.375 in. can be bent to radii of 3.5T. In all cases, surfaces must be free from defects that would act as stress risers and also free of all alpha case.
W E L D A B I L I T Y
ATI 425® titanium is easily weldable by standard techniques including GTAW and EBW processes. Bend ductility of welds has been shown to be better than in Ti-6-4. Annealed autogenous welds can typically be bent to radii of 5 – 6T in sheet and light plate gauges.
C O R R O S I O N D A T A
ATI Wah Chang has evaluated coupons of ATI 425® titanium in a variety of media. ATI 425® titanium performs similarly to Ti-6Al-4V and Ti-3Al-2.5V in marine environments and many media of the chemical process industry. Additional testing is in progress. Detailed information is available upon request.
P O T E N T I A L A P P L I C A T I O N S
The properties of ATI 425® titanium make it a good candidate for many applications. Its high strength and behavior will allow direct substitution for Ti-6-4, while its formability will help simplify fabrication. Areas where ATI 425® titanium could find wide-spread adoption include but are not limited to:
- Aerospace
- CPI Vessels
- Marine / Saltwater environments
- Ballistic Armor
- Medical Implants
- Recreation
C O N T A C T I N F O R M A T I O N
For inquiries and additional information please contact our Customer Service department at:
Toll Free: 888-924-4211 x6988
Fax: 541-697-6994
Email: custserv@wahchang.com
Web: www.wahchang.com
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