Description

ASTM A**3 is the Standard Specification for Seamless and Welded Steel Pipe for Low-Temperature Service.

ASTM A**3 standard covers wall seamless and welded carbon and alloy steel pipe intended for use at low temperatures. ASTM A**3 alloy pipe shall be made by the seamless or welding process with the addition of no filler metal in the welding operation. All seamless and welded pipes shall be treated to control their microstructure. Tensile tests, impact tests, hydrostatic tests, and nondestructive electric tests shall be made in accordance to specified requirements.

• This specification covers nominal (average) wall seamless and welded carbon and alloy steel pipe intended for use at low temperatures. Several grades of ferritic steel are included as listed in Table 1. Some product sizes may not be available under this specification because heavier wall thicknesses have an adverse affect on low-temperature impact properties.
• Supplementary Requirement S1 of an optional nature is provided. This shall apply only when specified by the purchaser.
• 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.
• Note 1: The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as “nominal diameter”, “size”, and “nominal size”.

Mainly Grade of ASTM A**3：

• ASTM A**3 Grade 1
• ASTM A**3 Grade 3
•  ASTM A**3 Grade 6

• All seamless and welded pipe shall be treated to control their microstructure by the following methods:
• Normalizing per A **3/A **3M**5 section 4.2.1.1; section 4.2.1.2 or section 4.2.1.3
• Quenched and Tempered per A **3/A **3M – *5 section 4.2.2.1
• Double Normalized and Tempered per A **3/A **3M – *5 section 4.2.2.2

For each reduction of 0.*1% carbon below 0.*0%, an increase of 0.*5% manganese above 1.*6% would be permitted to a maximum of 1.*5% manganese.
When Grade 6 is ordered under this specification, supplying an alloy grade that specifically requires the addition of any element other than those listed for the ordered grade is not permitted. However, the addition of elements required for the deoxidation of the steel is permitted.