(R) Welded Flash Controlled, High Strength (690 MPa Tensile Strength) Low Alloy Steel Hydraulic Tubing, Stress Relieved, Annealed for Bending, Double Flaring, Cold Forming, and Brazing
|Publication Date:||1 February 2019|
This SAE Standard covers stress relieved electric resistance welded flash controlled single wall high strength low alloy steel tubing intended for use in high-pressure hydraulic lines and in other applications requiring tubing of a quality suitable for bending, double flaring,cold forming and brazing. Material produced to this specification is not intended to be used for single flare applications due to the potential leak path caused by the ID weld bead. The grade of material produced to this specification is of micro-alloy content. Nominal reference working pressures for this tubing are listed in ISO 10763 and SAE J1065.
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 heataffected 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 from these processes. Performance testing as described in SAE J2551-2 will facilitate appropriate test recommendations.
Brazed and/or welded tube assembly configurations made to specific geometry and components in association with this material may require qualification testing in accordance with ISO 19879. Cold forming the tube end configurations avoids this systemic testing by not compromising the structural integrity of the 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