ASTM A860 / A860M
This specification covers wrought high-strength ferritic steel
butt-welding fittings of seamless and electric fusionwelded
construction covered by the latest revisions of ASME B16.9 and
MSS-SP-75. Butt-welding fittings differing from these ASME and MSS
standards shall be furnished in accordance with Supplementary
Requirement S58 of Specification A960/A960M. These fittings are for
use in high-pressure gas and oil transmission and distribution
systems.
Chemical Properties
| Element |
Composition % |
| Carbon |
0.20A |
| Manganese |
1.00 – 1.45 |
| Phosphorus |
0.030 |
| Sulfur |
0.010 |
| Silicon |
0.15 – 0.40B |
| Nickel |
0.50C |
| Chromium |
0.30C |
| Molybdenum |
0.25C |
| Copper |
0.35C |
| Titanium |
0.05 |
| Vanadium |
0.10 |
| Columbium |
0.04 |
| Vanadium + Columbium |
0.12 |
| Aluminum |
0.06 |
Note A: The carbon equivalent, as calculated by the following formula,
shall not exceed 0.42 %: CE = C + MN/6 + (Cr+Mo+V)/5 + Ni +
Cu/15
Note B: If vacuum carbon deoxidation is used, silicon shall not exceed 0.10
% by heat analysis and 0.12 % by product analysis.
Note C: The sum of Ni + Cr + Mo + Cu shall not exceed 1.0 %.
Mechanical Properties
| Grade |
Tensile strength, min, ksi [MPa] |
Yield strength, min,0.2 % offset, ksi [MPa] |
Elongation |
Standard round specimen, |
Rectangular specimen, for section thickness 5/16 in.
|
Rectangular specimen for section thickness less than 5/16
in.
|
| WPHY 42 |
60 [415] |
42 [290] |
85 [585] |
25 |
32 |
B |
| WPHY 46 |
63 [435] |
46 [315] |
88 [605] |
25 |
32 |
B |
| WPHY 52 |
66 [455] |
52 [360] |
91 [625] |
25 |
32 |
B |
| WPHY 60 |
75 [515] |
60 [415] |
100 [690] |
20 |
28 |
B |
| WPHY 65 |
77 [530] |
65 [450] |
102 [705] |
20 |
28 |
B |
| WPHY 70 |
80 [550] |
70 [485] |
105 [725] |
20 |
28 |
B |
Note B:
For each 1/32 in. [0.79 mm] decrease in section thickness
below 5/16 in. [7.94 mm] a deduction 1.5 % from the 30 %
shown above is permitted. Where the section thickness lies between
two values defined above, the minimum elongation value is determined
by the following equation:
E = 5 48t115.00
where: E = elongation in 2 in. [50 mm], and t = actual thickness of
specimen, in. B These requirements are intended to minimize fracture
initiation. The requirements are not intended to give assurance
against fracture propagation.