ASTM A524 Seamless Carbon Steel Pipe for Atmospheric and Lower-Temperature Service

ASTM A524 seamless carbon steel pipe is designed primarily for pressure piping systems operating at atmospheric and moderately lower temperatures. It is manufactured from killed, fine-grain carbon steel and is supplied in either Grade I or Grade II according to wall thickness.

The pipe may be produced by hot finishing or cold drawing and must receive heat treatment after forming. It is suitable for welding, bending, flanging, close coiling, and similar fabrication operations. Typical supply includes dimensional inspection, tensile testing, flattening or bend testing, and hydrostatic or approved nondestructive examination.

ASTM A524/A524M covers pipe sizes from NPS 1/8 to NPS 26, corresponding to DN 6 to DN 650. Dimensions are generally supplied according to ASME B36.10M unless otherwise specified by the purchaser.

Specifications

Main Features

Fine-Grain Killed-Steel Construction

ASTM A524 pipe must be produced from fully killed steel using fine-grain practice. This controlled steelmaking route improves structural uniformity and supports reliable forming, welding, and pressure-service performance.

Controlled Carbon and Manganese Content

The maximum carbon content is limited to 0.21%, while manganese is controlled between 0.90% and 1.35%. This composition provides a practical balance between strength, ductility, and weldability.

Defined Strength According to Wall Thickness

Grade selection is determined by wall thickness:

• Grade I applies to wall thicknesses of 9.52 mm and below.

• Grade II applies to wall thicknesses greater than 9.52 mm.

Grade I provides a minimum yield strength of 240 MPa. Grade II provides a minimum yield strength of 205 MPa with increased minimum elongation for thicker-wall pipe.

Mandatory Post-Forming Heat Treatment

Both hot-finished and cold-drawn pipes are reheated to a temperature above 845°C. They are subsequently cooled in air or inside the cooling chamber of a controlled-atmosphere furnace.

This treatment reduces residual forming stresses and produces more consistent mechanical properties throughout the pipe section.

Suitable for Secondary Fabrication

ASTM A524 pipe is intended to remain suitable for:

• Welding

• Cold bending

• Flanging

• Close coiling

• Machining

• End forming

• Pressure-system assembly

Manufacturing procedures should still be qualified according to the final equipment code and operating conditions.

Our Advantages

Wall-Thickness-Based Grade Control

A frequent purchasing issue is ordering Grade I or Grade II without confirming the actual nominal wall thickness. ASTM A524 does not treat these as freely interchangeable material grades.

Our material review process matches the ordered wall thickness with the correct classification:

• Wall thickness up to and including 9.52 mm: Grade I

• Wall thickness above 9.52 mm: Grade II

This prevents incorrect grade identification on quotations, manufacturing records, pipe markings, and inspection certificates.

Traceable Heat Treatment and Material Documentation

Purchasers of pressure-service pipe commonly require proof that the material has received the specified post-forming heat treatment.

Production records can include:

• Heat number

• Manufacturing route

• Heat-treatment condition

• Chemical analysis

• Tensile test results

• Hydrostatic or nondestructive test results

• Final dimensions

• Product marking

• EN 10204 3.1 inspection certificate

This traceability supports incoming inspection and pressure-equipment documentation review.

Dimensional and Testing Requirements Confirmed Before Production

Pipe dimensions alone are not sufficient to define an ASTM A524 order. The purchaser should also specify the required schedule, pipe end, test method, length, surface condition, and inspection documentation.

Before manufacturing, the order can be reviewed for:

• NPS or outside diameter

• Nominal wall thickness or schedule

• Grade I or Grade II

• Hot-finished or cold-drawn condition

• Fixed or random length

• Plain or beveled ends

• Hydrostatic or nondestructive testing

• Surface protection

• Marking requirements

• Inspection certificate type

This reduces technical deviations between the purchase order, production plan, and final inspection documents.

Execution Standards

Application

Low-Temperature Liquid Storage Tank Transfer Piping

ASTM A524 seamless carbon steel pipe can be used for transfer piping connected to low-temperature liquid storage tanks where the specified design temperature, design pressure, corrosion allowance, and applicable piping code permit carbon steel construction.

In this application, the pipe transports process liquid between the storage vessel, pump unit, valve assembly, and downstream process equipment. Seamless construction eliminates the longitudinal weld seam, while the fine-grain killed-steel structure supports forming and welding during system fabrication.

The final material selection must be confirmed against the minimum design-metal temperature and impact-testing requirements of the applicable engineering code. ASTM A524 should not be assumed suitable for cryogenic service without a complete design review.

Chemical Composition

Mechanical Properties

Manufacturing and Heat Treatment

The steel must be fully killed and manufactured using fine-grain practice. It may be produced by electric-furnace, basic-oxygen, or another process permitted by the applicable edition of the standard.

Pipe may be hot finished or cold drawn, subject to size-related manufacturing provisions. After forming, the pipe must be reheated above 845°C and cooled in air or in the cooling chamber of a controlled-atmosphere furnace.

The typical production sequence includes:

Steelmaking and chemical analysis
Billet preparation
Piercing
Hot rolling or cold drawing
Heat treatment
Straightening
End finishing
Dimensional inspection
Mechanical testing
Hydrostatic or nondestructive testing
Surface protection
Marking and certification

Inspection and Testing