Microstructures, phases, and phase transformations in Ti-6Al-4V alloy specimens containing 0, 10, 20, and 30 at. pct hydrogen were investigated using optical microscopy (OM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and microhardness testing. Alloying with hydrogen was achieved by holding the specimens in a pure hydrogen atmosphere of different pressures at 780 ЊC for 24 hours. The phases present in the temperature range of 20 ЊC to 1000 ЊC were determined by microstructural characterization of the specimens quenched from different temperatures. Increasing the hydrogen addition from 0 to 30 at. pct lowered the beta-transus temperature of the alloy from 1005 ЊC to 815 ЊC, significantly slowed down the kinetics of the beta-to-alpha transformation, and led to formation of an orthorhombic martensite instead of the hexagonal martensite found in quenched specimens containing 0 pct H. A hydride phase was detected in specimens containing 20 and 30 at. pct hydrogen. The time-temperature-transformation (TTT) diagrams for beta-phase decomposition were determined at different hydrogen concentrations. The nose temperature for the beginning of the transformation decreased from 725 ЊC to 580 ЊC, and the nose time increased from 12 seconds to 42 minutes when the hydrogen concentration was increased from 0 to 30 at. pct.

Titanium alloys have been found to provide substantial cost and operational benefits in offshore production and drilling systems. Properties such as high strength, low density, exceptional corrosion resistance, and inherent flexibility have made the alloys a viable choice for equipment including drilling risers, drill pipe, and tapered stress joints. In most cases the most successful applications will marry titanium and steel together in a hybrid fashion. This paper provides an overview of known and potential benefits of certain high strength titanium alloys in a variety of offshore applications.For more information, contact R.W. Schutz,

Author's Note: Do not expect good club design and advanced materials to cure all golfing woes. They can help, but they are not a panacea for a bad swing and/or lack of strength. For these problems, see your local, friendly Professional Golfers' Association professional.In the sporting goods industry, the application of game-improving advanced materials has resulted in titanium golf clubs attaining near-mythical status. These improvements have not come cheaply, however, and titanium clubs are losing ground to creative designs that employ combinations of lower cost materials. As a result, unless the cost of titanium can be lowered, the metal will see its share of the market become significantly reduced by the judicious use of lower-cost materials.

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