ASTM A178/A178M

ASTM A178 Standard Specification for Electric-Resistance-Welded Carbon Steel and Carbon-Manganese Steel Boiler and Superheater Tubes

ASTM A178/A178M specification covers standards for electric-resistance-welded tubes with minimum-wall-thickness made of carbon steel and carbon-manganese steel to be used in boiler tubes, boiler flues, superheater flues, and safe ends. The steel shall be of Grades A (low-carbon steel), C (medium-carbon steel), or D (carbon-manganese steel). All tubes shall be submitted to heat treatment after welding, followed by cooling. The steel shall conform to stated compositions of carbon, manganese, phosphorus, sulphur, and silicon. Grades C and D shall conform to given tensile requirements, that is tensile strength, yield strength, and elongation. The material shall also be subjected to flattening, flange, tension, reverse flattening, and hydrostatic (or nondestructive electric) tests. Crush test shall also be performed if asked by the purchaser. Minimum elongation values are also given.

Scope

1.1 This specification2 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.

1.2 This specification covers Grades A, C, and D with differing chemical requirements (Section 6 and Table 1), differing tensile requirements (Section 9 and Table 2), and differing crush and mechanical testing requirements (Sections 10 and 11).

NOTE 1: Grades C and D tubes are not suitable for safe-ending for forge welding.

1.3 The tubing 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.

1.4 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.

1.5 Optional supplementary requirements are provided and when desired, shall be so stated in the order.

1.6 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.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Different name

Condenser steel tube,heat-exchanger tube,low carbon steel pipe,Resistance welded steel tube ,Bolier flues,Spoerheater flues and safe ends,ERW carbon steel pipes.

Chemical Composition of ASTM A178

Product Analysis

1. When requested on the purchase order, a product analy- sis shall be made by the manufacturer or supplier from one tube per 100 pieces for sizes over 3 in. [76.2 mm] and one tube per 250 pieces for sizes 3 in. [76.2 mm] and under; or when tubes are identified by heat, one tube per heat shall be analyzed. The chemical composition thus determined shall conform to the requirements specified.
2. If the original test for product analysis fails, retests of two additional lengths of flat-rolled stock or tubes shall be made. Both retests, for the elements in question, shall meet the requirements of the specification; otherwise all remaining material in the heat or lot (Note 2) shall be rejected or, at the option of the producer, each length of flat-rolled stock or tube may be individually tested for acceptance. Lengths of flat- rolled stock or tubes which do not meet the requirements of the specifications shall be rejected.

Mechanical Property of ASTM A178

Grade C & Grade D tubes shall conform to the requirements -tensile properties prescribed below

Outside diameter and Wall Thickness Tolerance of ASTM A178/A178M

Referenced Documents

• A450/A450M Specification for General Requirements for Carbon,Ferritic Alloy,and Austenitic Alloy steel tubes.
• E213 Practice for Ultrasonic Examination of Metal pipe and tubing.
• E273 Practice for Ultrasonic Examination of Longitudinal Welded Pipe and Tubing.

A450/A450M

ASTM A450 covers carbon and low alloy steel tube. Steel samples shall be melt processed and shall either be ingot cast or strand cast. Heat and product analyses shall be performed on the steel materials. Steel specimens shall also undergo tensile tests and shall conform to required values of yield strength and elongation. Flattening test, reverse flattening test, flaring test, flange test, hardness test, hydrostatic test, air underwater pressure test, and nondestructive tests shall be performed on the steel materials.

Manufacturing Process

Heat treatment:

After welding,all tubes shall be heat treated at a temperature of 1650°F(900℃) 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℃)or higher.

Surface Condition:

Finished tubes shall be free of scale,A slight amount of oxidation will not be considered as scale.

Mechanical Tests Required:

Flattenting Test/Flaring test/Flange test/Crush test/Tension test/Reverse Flattening test/Hydrostatic or Nondestructive Electric Test

Usage

Used in boiler, superheater, heat-exchanger and pressure equipment in Petrochemical factory, Refinery factory, sugar mill, power plant, power plant, shipbuilding.

Manufacture & Heat Treatment

The ASTM A178 Grade D steel shall be killed. ASTM A178 tubes shall be made by electric-resistance welding process. 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°F] or higher.

Testing & Inspection

ERW tubes made from ASTM A178 steel may be tested or inspected in the following ways covering crush test, flattening test, flange test, tension test, reverse tension test, hydrostatic test, nondestructive electric test, dimension inspection, visual examination, as well as ultrasonic inspection.

Material Comparison Tables (ASTM ℃KS, JIS, DIN, BS, NBN, NF, UNI)

A 178 C-Steel Electric-Resistance-Welded Boiler Tubes

Related ASTM A178/A178M