ASTM A847–99a (R2003) pdf free.Standard Specification for Cold-Formed Welded and Seamless High-Strength, LowAlloy Structural Tubing with Improved Atmospheric Corrosion Resistance.
This specification covers cold-formed welded and seamless high-strength, low-alloy round, square, rectangular, or special shaped structural tubing for welded, riveted, or bolted construction of bridges and buildings and for general structural purposes where high strength and enhanced atmospheric corrosion resistance are required (Note 1). The atmospheric corrosion resistance of this steel in most environments is substantially better than carbon steel with or without copper addition (Note 2). When properly exposed to the atmosphere, this steel can be used bare (unpainted) for many applications. When this steel is used in welded construction, the welding procedure shall be suitable for the steel and the intended service.
3. Ordering nformation
3. 1 Orders for material under this specification should
include the following, as required, to describe the desired
material adequately
3.1.1 ASTM specification number.
1. 2 Quantity(feet, metres, or number of lengths)
3.1.3 Name of material (cold-formed tubing).
3.1.4 Method of manufacture (welded or seamless).
3. 1.5 Size( outside diameter and nominal wall thickness for round tubing and the outside dimensions and nominal wall thickness for square and rectangular tubing)
3.1.6 Length (specific or random, see 10.3 3.1.7 End condition (see 14.2)
3.1.8 BuIr removal (see 14.2)
3.1.9 Certification(see Section 17) 3.1.10 End use. and
3. 1. 11 Special requirements.
4. Process
4.1 The steel shall be made by one or more of the following processes: open hearth, basic oxygen, or electric furnace.
5. Manufacture
5.1 The tubing shall be made by a welded or seamless process
2 Welded tubing shall be made from flat-rolled steel by the electric-resistance welding or electric-fusion welding pro- cess. The longitudinal butt joint shall be welded across its hickness in such a manner that the structural desion strength of the tubing section is assured.
5.2.1 Structural tubing welded by the electric-resistance method is normally furnished without removal of inside flash.
6. Chemical CoInposition
6. 1 The choice and use of alloying elements combined with carbon. manganese. phosphorus. sulphur. and copper shall be within the limits prescribed in Section 7 to give the mechanical properties prescribed in Table 1 and to provide the atmospheric corrosion resistance of 1.1. The choice and use of these elements shall be made by the manufacturer and included and reported in the heat analysis to identir the type of steel applied. Elements conunonly added include chromium. nickel. silicon, vanadium, titanium. and zirconium. For Specification A 847 material, the atmospheric corrosion-resistance index. calculated on the basis of the chemical composition of the steel as described in Guide G 101. shall be 6.0 or higher.
Nom 3—The user is cautioned that the Guide G 101 predictive equation for calculation of an atmospheric corrosion-resistance index has been verified oniy for the composition limits stated in that guide.
7. Heat Analysis
7.1 Each heat analysis shall confonu to the requirements specified in Table 2 for heat analysis.