This specification covers carbon and high-strength low alloy steel structural shapes, plates and bars, and quenched and tempered alloy steel for structural plates intended for use in bridges.
Heat analysis shall be used to determine the percentage of carbon, manganese, phosphorus, sulfur, silicon, and copper for the required chemical composition.
A tension test shall be used to determine the required tensile properties such as tensile strength, yield strength, and elongation. Materials shall undergo: (1) an impact test for non-fracture critical and fracture critical members; and (2) a Brinell hardness test for Grades 100 and 100W. Atmospheric corrosion resistance shall also be determined.
Scope
1.1 This specification covers carbon and high-strength low-alloy steel structural shapes, plates, and bars, quenched and tempered alloy steel, and stainless steel for structural plates intended for use in bridges. Twelve grades are available in five yield strength levels as follows:
|
Grade U.S. [SI] |
Yield Strength, ksi [MPa] |
|
|
|
|
36 [250] |
36 [250] |
|
50 [345] |
50 [345] |
|
50S [345S] |
50 [345] |
|
QST 50 [QST 345] |
50 [345] |
|
QST 50S [QST 345S] |
50 [345] |
|
50W [345W] |
50 [345] |
|
HPS 50W [HPS 345W] |
50 [345] |
|
50CR [345CR] |
50 [345] |
|
QST 65 [QST450] |
65 [450] |
|
QST 70 [QST485] |
70 [485] |
|
HPS 70W [HPS 485W] |
70 [485] |
|
HPS 100W [HPS 690W] |
100 [690] |
1.2 Grade HPS 70W [HPS 485W] or HPS 100W [HPS 690W] shall not be substituted for Grades 36 [250], 50 [345], 50S [345S], 50W [345W], or HPS 50W [HPS 345W]. Grade 50W [345W], or HPS 50W [HPS 345W] shall not be substituted for Grades 36 [250], 50 [345] or 50S [345S] without agreement between the purchaser and the supplier.
1.3 When the steel is to be welded, it is presupposed that a welding procedure suitable for the grade of steel and intended use or service will be utilized. See Appendix X3 of Specification A6/A6M for information on weldability.
1.4 For structural products to be used as tension components requiring notch toughness testing, standardized requirements are provided in this standard, and they are based upon American Association of State Highway and Transportation Officials (AASHTO) requirements.
1.5 Supplementary requirements are available but shall apply only if specified in the purchase order.
1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.7 For structural products produced from coil and furnished without heat treatment or with stress relieving only, the additional requirements, including additional testing requirements and the reporting of additional test results, of Specification A6/A6M apply.
What is ASTM A709 material?
The ASTM A709 is the Standard Specification for Structural Steel for Bridges and encompasses carbon, high-strength low-alloy, and quenched and tempered alloy steels used as structural plates in the construction of bridges. SSAB offers the following five grades of A709; 36, 50, 50W, HPS 50W and HPS 70W.
What is A709 grade 50W steel?
The ASTM A709-50W structural steel product grade is a high-strength low alloy (HSLA) steel that demonstrates atmospheric corrosion resistance better than many steels with a corrosion index of 6.0 and higher, while providing a minimum tensile strength of 70 ksi.
What is the difference between ASTM A36 and A709?
ASTM A709 grade 36 steel plate has improved corrosion resistance and can be used in outdoor applications. A36 plates are more suitable for general structural purposes.
