Designation: A199/A199M | ||||||||
SPECIFICATION FOR SEAMLESS COLD-DRAWN INTERMEDIATE ALLOY-STEEL HEAT-EXCHANGER AND CONDENSER TUBES |
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Scope | ||||||||
This specification covers several grades of minimum-wall-thickness, chromium-molybdenum and chromium-molybdenum-silicon, seamless, cold-drawn, intermediate alloy steel tubes for heat exchangers, condensers, and similar heat transfer apparatus. The tubing sizes usually furnished to this specification are 1⁄8 to 3 in. [3.2 to 76.2 mm] in outside diameter. Tubing having other dimensions may be furnished provided such tubes comply with all other requirements of this specification. Mechanical property requirements do not apply to tubing smaller than 1⁄8 in. [3.2 mm] in inside diameter or 0.015 in. [0.4 mm] in thickness. The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order. |
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Manufacture | ||||||||
Tubes shall be made by the seamless process and shall be cold drawn. | ||||||||
Heat Treatment | ||||||||
After the final cold-draw pass, Grade T-11 tubes shall be heat treated at 1200°F [650°C] or higher and all other grades except T91 shall be heat treated at 1250°F [675°C] or higher. For Grade T91, the tubes shall be normalized from the temperature range of 1900–2000°F [1400–1095°C] and tempered at 1305°F (730°C) minimum | ||||||||
Hardness Requirements | ||||||||
The tubes fabricated from Grades T3b, T4, T5, T11, T21, and T22 shall have a hardness number not exceeding 85 HRB. For tubes fabricated from Grade T9, the maximum hardness shall be 89 HRB and for Grade T91 the maximum hardness shall be 98 HRB. | ||||||||
Mechanical Tests Required | ||||||||
Tension Test — One tension test shall be made on a specimen for lots of not more than 50 tubes. Tension tests shall be made on specimens from two tubes for lots of more than 50 tubes. Flattening Test — One flattening test shall be made on specimens from each end of one finished tube, not the one used for the flaring test, from each lot. Flaring Test — One flaring test shall be made on specimens from each end of one finished tube, not the one used for the flattening test, from each lot. Hardness Test — Brinell or Rockwell hardness tests shall be made on specimens from two tubes from each lot. Hydrostatic Test — Each tube shall be subjected to the hydrostatic test, or, instead of this test, a nondestructive electric test may be used when specified by the purchaser. |
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Chemical Requirements | ||||||||
Composition, % | ||||||||
Grade | Carbon | Manganese | Phosphorus, max | Sulfur, max | Silicon | Chromium | Molybdenum | Others |
T4 | 0.05 min–0.15 max | 0.30–0.60 | 0.025 | 0.025 | 0.50–1.00 | 2.15–2.85 | 0.44–0.65 | . . . |
T5 | 0.15 max | 0.30–0.60 | 0.025 | 0.025 | 0.50 max | 4.00–6.00 | 0.45–0.65 | . . . |
T9 | 0.15 max | 0.30–0.60 | 0.025 | 0.025 | 0.25–1.00 | 8.00–10.00 | 0.90–1.10 | . . . |
T11 | 0.05 min–0.15 max | 0.30–0.60 | 0.025 | 0.025 | 0.50–1.00 | 1.00–1.50 | 0.44–0.65 | . . . |
T21 | 0.05 min–0.15 max | 0.30–0.60 | 0.025 | 0.025 | 0.50 max | 2.65–3.35 | 0.80–1.06 | . . . |
T22 | 0.05 min–0.15 max | 0.30–0.60 | 0.025 | 0.025 | 0.50 max | 1.90–2.60 | 0.87–1.13 | . . . |
T91 | 0.08–0.12 | 0.30–0.60 | 0.020 | 0.010 | 0.20–0.50 | 8.00–9.50 | 0.85–1.05 | Ni 0.40 max; V |
0.18–0.25; Cb | ||||||||
0.06–0.10; N | ||||||||
0.03–0.07; Al | ||||||||
0.04 max | ||||||||
TENSILE REQUIREMENTS | ||||||||
All Grades Except T91 | Grade T91 | |||||||
Tensile strength, min., ksi [MPa] | 60 [415] | 85 [585] | ||||||
Yield strength, min., ksi [MPa] | 25 [170] | 60 [415] | ||||||
Elongation in 2 in., or 50 mm, min., % | 30 | 20 | ||||||
For longitudinal strip tests a deduction shall be made for each 1⁄32 in. [0.8 mm] decrease in wall thickness below 5⁄16 in. [8 mm] from the basic minimum elongation of the following percentage points | 1.501 | 1.001 | ||||||
When standard round 2 in. or 50 mm gage length or smaller proportionally sized specimen with the gage length equal to 4D (four times the diameter) is used |
22 | |||||||
Notes: | ||||||||
(1) The following table gives the computed minimum values. | ||||||||
(2) Calculated elongation requirements shall be rounded to the nearest whole number. | ||||||||
Wall Thickness, in. [mm] | Elongation in 2 in., | or 50 mm, min., %2 | ||||||
5⁄16 (0.312) [8] | 30 | 20 | ||||||
9⁄32 (0.281) [7.2] | 28 | 19 | ||||||
1⁄4 (0.250) [6.4] | 27 | 18 | ||||||
7⁄32 (0.219) [5.6] | 26 | 17 | ||||||
3⁄16 (0.188) [4.8] | 24 | 16 | ||||||
5⁄32 (0.156) [4] | 23 | 15 | ||||||
1⁄8 (0.125) [3.2] | 21 | 14 | ||||||
3⁄32 (0.094) [2.4] | 20 | 13 | ||||||
1⁄16 (0.062) [1.6] | 18 | 12 | ||||||
0.062 to 0.035 [1.6 to 0.9], excl | 17 | 12 | ||||||
0.035 to 0.022 [0.9 to 0.6], excl | 16 | 11 | ||||||
0.022 to 0.015 [0.6 to 0.4], incl | 16 | 11 | ||||||
GENERAL NOTE: The above table gives the computed minimum elongation values for each 1⁄32 in. [0.8 mm] decrease in wall thickness. Where the wall thickness lies between two values shown above, the minimum elongation value shall be determined by the following equation: For all Grades except T91: E = 48t + 15.00 [E = 1.87t + 15.00] For Grade T91: E = 32t + 10.00 |
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where: |
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E = elongation in 2 in., or 50 mm, % and | ||||||||
t = actual thickness of specimen, in. [mm] | ||||||||
NUMBER OF TUBES IN A LOT HEAT TREATED BY THE CONTINUOUS PROCESS |
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Side of Tube | Size of Lot | |||||||
2 in. [50.8 mm] and over in outside diameter and 0.200 in. [5.1 mm] and over in wall thickness | not more than 50 tubes | |||||||
Less than 2 in. [50.8 mm] but over 1 in. [25.4 mm] in outside diameter or over 1 in. [25.4 mm] in outside diameter and under 0.200 in. [5.1 mm] in wall thickness | not more than 75 tubes | |||||||
1 in. [25.4 mm] or less in outside diameter | not more than 125 tubes |
Seamless Tube A199 Grade T91 | Seamless Tube A199 Grade T22 | Seamless Tube A199 Grade T21 |
Seamless Tube A199 Grade T11 | Seamless Tube A199 Grade T9 | Seamless Tube A199 Grade T5 |
Seamless Tube A199 Grade T4 |
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