ASTM A178 Grade D Electric-Resistance-Welded Steel Tubes
ASTM A178 Grade D Electric-Resistance-Welded Carbon-Manganese Steel Boiler and Superheater Tubes.The steel for Grade D shall be killed.Tubes shall be made by electric-resistance welding.
Description
ASTM A178 Grade D Electric-Resistance-Welded Carbon-Manganese Steel Boiler and Superheater Tubes
ASTM A178 specification covers minimum-wall-thickness,electric-resistance-welded tubes made of carbon steel and carbon-manganese steel intended for use as boiler tubes, boiler flues, superheater flues, and safe ends.
ASTM A178 Grade D Carbon-Manganese Steel Boiler Tubes are not suitable for safe-ending for forge welding.
ASTM A178 Grade D Carbon-Manganese Steel Boiler Tubes Quick Details
Type：Electric-Resistance-Welded
Outside Diameter ：12.7mm-127mm
Wall thickness：0.9mm-9.1mm
Length：6000mm、12000m or specified length as required.
Type of End-Finish：Plain End、Beveled End、Treaded
Surface treatment: Tubes will be varnished (Outside only) to prevent rust.
ASTM A178 Grade D Carbon-Manganese Steel Boiler Tubes sizes and thicknesses usually furnished to this specification are 1 ⁄ 2 to 5 in. [12.7 to 127 mm] in outside diameter and 0.035 to 0.360 in. [0.9 to 9.1 mm], inclusive, in minimum wall thickness. Tubing having other dimensions may be furnished, provided such tubes comply with all other requirements of this specification.
Manufacture
The steel for Grade D shall be killed.
Tubes shall be made by electric-resistance welding.
Heat Treatment
After welding, all tubes shall be heat treated at a temperature of 1650°F [900°C] or higher and followed by cooling in air or in the cooling chamber of a controlled-atmosphere furnace. Cold-drawn tubes shall be heat treated after the final cold-draw pass at a temperature of 1200°F[650°C] or higher.
Chemical Composition
| Element | Composition, % |
| Grade D, Carbon-Manganese Steel | |
| Carbon | 0.27 max |
| Manganese | 1.00–1.50 |
| Phosphorus, max | 0.030 |
| Sulfur, max | 0.015 |
| Silicon | 0.10 min |
Tensile Requirements
| Grade D | |
| Tensile strength, min, ksi [MPa] | 70 [485] |
| Yield strength, min, ksi [MPa] | 40 [275] |
| Elongation in 2 in. or 50 mm, min, % | 30 |
| For longitudinal strip tests a deduction 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 shall be made. |
1.50 A |
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.
Mechanical Tests Required
Flattening Test:
For Grades D, one flattening test shall be made on specimens from each of two tubes from each lot or fraction thereof.
Flange Test:
For Grades D, one flange test shall be made on specimens from each of two tubes from each lot or fraction thereof. The width of the flange shall not be less than 75 % of that specified in Specification A 450/A 450M.
Crush Test
When required by the purchaser, crushing tests shall be made on sections of tube 2 1 ⁄ 2 in. [63 mm] in length which shall stand crushing longitudinally without cracking, splitting, or opening at the weld,
Tension Test
—For Grades D, one tension test shall be made on specimens from each of two tubes from each lot.
Reverse Flattening Test
—One reverse flattening test shall be made on each 1500 ft [450 m] of finished tubing.
Hydrostatic or Nondestructive Electric Test
—Each tube shall be subjected to either the hydrostatic or the nonde-structive electric test. The purchaser may specify which test is to be used
Product Marking
In addition to the marking prescribed in Specification A 450/A 450M, the letters “ERW” shall be legibly stenciled on each tube, or marked on a tag attached to the bundle or box in which the tubes are shipped.