ASTM A249/A249M covers Austenitic stainless steels welded tube,intend as boiler tube,heat exchanger tube,super heater tubes,condenser tubes,and intended for other high temperature service.
Stainless steel grades and chemical composition:
Manufacture:automatic welding process with no addition of filler metal,subsequent to welding and prior to final heat treatment,the tubes shall be cold worked either in both weld and base metal or in weld metal only.
Testing and inspection:
- Reverse-Bend Test
- Tension Test
- Flattening Test
- Flange Test
- Hardness Test—Brinell or Rockwell hardness tests
- Hydrostatic or Nondestructive Electric Test
- Grain Size
- Air Underwater Pressure Test(option)
- Intergranular Corrosion Testc
- Weld Decay Test
Permissible Variations in Dimensions:
Dimensional tolerances other than wall thickness tolerances shall be in accordance with Specification A 1016/A 1016M. Wall thickness tolerances shall be 610 % of nominal wall for all tubing sizes.
|＜25.40mm||±0.10mm||±10.00%||OD＜50.8mm +3.0mm -0mm OD≥50.8mm +5.0 -0mm|
The tubes, after final heat treatment, shall be chemically descaled or pickled free of scale. When bright annealing is used, pickling or chemical descaling is not necessary.
See A249 welded stainless steel tube