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Friday, 16 April 2010

Tungsten heavy alloy grades ASTM B 777-99

Tungsten heavy alloy grades ASTM B 777-99

ASTM B 777-99

Class

1

2

3

4

Tungsten Nominal %

90

92.5

95

97

Density (g/cc)

16.85-17.25

17.15-17.85

17.75-18.35

18.25-18.85

Hardness (HRC) Max

32

33

34

35

Ultimate Tensile Strength

ksi

110

110

105

100

Mpa

758

758

724

689

Yield Strength at 0.2% off-set

ksi

75

75

75

75

Mpa

517

517

517

517

Elongation, %

5

5

3

2

ASTM B777-99 Standard Specification for Tungsten Base, High-Density Metal

1.his specification covers the requirements for four classes of machinable,high-density tungsten base metal produced by consolidation of metal powder mixtures of which the composition is mainly tungsten. This material specification may be used for bare parts or be used for parts that may be coated with other materials for protection against corrosion and abrasion.

2. Intended Use -Parts made from this material are intended for uses such as weights or counter-balances in static or dynamic balancing high-speed rotating inertia members, radiation shielding, hypervelocity impact, and vibration-damping applications.

3.Special Applications -For particular applications, properties or requirements may be important. These alloys may contain elements which make them magnetic. Where freedom from magnetic response is required, this should be specified in the purchase order. Class 4 is not available in a non-magnetic grade. For purposes of this specification, non-magnetic characteristics are defined as material having a maximum magnetic permeability of 1.05. Also for special applications involving large sections, methods for determining internal quality, such as mechanical tests on specimens from these larger sections or suitable nondestructive tests may be applied. If required, these additional tests shall be specified in the purchase order.

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