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astm a178 erw steel pipe

Introduction To ASTM A178 ERW Steel Pipe

Date:2023-11-20View:17Tags:astm a178 erw steel pipe

ASTM A178 is a specification that covers electric-resistance-welded (ERW) carbon steel and carbon manganese steel boiler and superheater tubes. These tubes are intended for use in boilers, flues, and superheaters with high-pressure service. In this passage, Union Steel Industry will introduce ASTM A178 ERW steel pipe in detail.


ASTM A178 ERW Steel Pipe


Chemical Composition of ASTM A178 ERW Steel Pipe:

Element %

ASTM A178 Gr A / SA178A

ASTM A178 Gr C / SA178C

ASTM A178 Gr D / SA178D

Low carbon steel

Medium Carbon Steel

Manganess Steel

C

0.06-0.18

0.35 Max

0.27 Max

Mn

0.27-0.63

0.80 Max

1.00-1.50

P

0.035

0.035

0.030

S

0.035

0.035

0.015

Si

-

-

0.10 Min.


Mechanical Properties of ASTM A178 ERW Steel Pipe:

Item

ASTM A178 Gr A / SA178A

ASTM A178 Gr C / SA178C

ASTM A178 Gr D / SA178D

Tensile strength, min, ksi [MPa]

47[325]

60[415]

70[485]

Yield strength, min, ksi [MPa]

26[180]

37[255]

40[275]

Elongation in 2 in. or 50mm, min, %

35

30

30

For longitudinal strip tests a deduction

1.50A

1.50A

1.50A

Each1⁄32-in[0.8mm] decrease in wall thickness below 5⁄16in. [8mm]




From the basic minimum elongation of the following percentage points shall be made





Outside Diameter and Wall Thickness Tolerance of ASTM A178 ERW Steel Pipe:

Outside Diameter Tol

Wall thickness Tol

OD < 50

±0.05mm

S < 4mm

±12.5%

OD > 50

±1%

4--20mm

+15/-12.5%

S≧20mm

±12.5%


Heat Treatment of ASTM A178 ERW Steel Pipe:

ASTM A178 ERW steel pipes are required to undergo the electric-resistance welding process. Subsequent to welding, all pipes must undergo a heat treatment at a temperature equal to or exceeding 1650°F [900°C], followed by either air cooling or cooling within the controlled atmosphere of a furnace. In the case of cold-drawn tubes, a heat treatment is mandated after the final cold-draw pass at a temperature of 1200°F [650°C] or higher.


Testing and Inspection of ASTM A178 ERW Steel Pipe:

- Flattening tests

- Flaring tests

- Hardness tests

- Nondestructive electric tests


Application of ASTM A178 ERW Steel Pipe:

ASTM A178 ERW steel pipes are primarily used for conveying steam, water, gas, and other fluids at high temperatures and pressures in boilers and superheaters.