(R) Welded and Cold-Drawn, High Strength (500 MPa Tensile Strength) Hydraulic Tubing, for Bending, Flaring, Cold Forming, Welding and Brazing
|Publication Date:||1 January 2018|
This specification covers sub-critically annealed or normalized electric resistance welded and cold-drawn single-wall high strength steel tubing intended for use in hydraulic pressure lines and in other applications requiring tubing of a quality suitable for bending, flaring, cold forming, welding and brazing. Nominal reference working pressures for this tubing are listed in ISO 10763 for metric tubing and SAE J1065 for inch tubing.
This specification also covers SAE J2614 Type-A tubing. The mechanical properties and performance requirements of standard SAE J2614 and SAE J2614 Type-A are the same. The designated differences of Type-A tubing do not imply that Type-A tubing is in anyway inferior to standard SAE J2614. The Type-A designation is meant to address unique manufacturing differences between sub-critically annealed and normalized tubing.
CAUTION: Sub-critically annealed steels are often produced using anneal temperatures below the Lower Critical Temperature (AC1) of the given steel to achieve the desired strength levels. Welding, brazing, or other processing methods that subject the tube material or assembly to temperatures near or above AC1 might initiate isothermal transformation of the tube microstructure and compromise the strength of the tube in the heat affected zone by further annealing the tube. Therefore, ISO 10763 and SAE J1065 nominal reference working pressures might not be applicable. It is recommended that the user and the fabricator validate and agree that the tube assembly design and pressure ratings are not compromised beyond system design by these processes. Performance testing as described in SAE J2551-2 will facilitate appropriate test recommendations.
Tube assembly configurations made to specific geometry and components requiring thermal attachment methods in association with the sub-critically annealed material, may require qualification testing in accordance with ISO 19879. The use of Type-A material avoids this systemic testing as thermal processes will not compromise the structural integrity of the Type-A tube material.
In an effort to standardize within a global marketplace and ensure that companies can remain competitive in an international market, it is the intent to convert to metric tube sizes which will:
• Lead to one global system
• Guide users to preferred system
• Reduce complexity
• Eliminate inventory duplications