本规范涵盖了用于液压管路和其他要求管材质量适合弯曲、扩口、冷成型和钎焊的应用中的应力消除退火电阻焊和冷拔单壁高强度低合金钢管。根据本规范生产的材料等级为微合金含量。ISO 10763和SAE J1065中列出了该管道的标称参考工作压力。警告:亚临界退火钢通常使用低于给定钢的较低临界温度（AC1）的退火温度生产，以达到所需的强度水平。将管材料或组件置于接近或高于AC1的温度下的焊接、钎焊或其他加工方法可能会引发管微观结构的等温转变，并通过对管进行进一步退火，降低热影响区内管的强度。 因此，ISO 10763和SAE J1065标称参考工作压力可能不适用。建议用户和制造商验证并同意，除了这些工艺的系统设计外，管道组件设计和压力额定值不会受到影响。SAE J2551-2中所述的性能测试将促进适当的测试建议。根据与该材料相关的特定几何形状和部件制成的钎焊和/或焊接管组件配置可能需要根据ISO 19879《液压流体动力连接试验方法》进行鉴定试验。管端连接件的冷成型代替了钎焊和焊接等热工艺，通过不损害管材料的结构完整性，避免了这种系统测试。 为了在全球市场内实现标准化，并确保公司在国际市场上保持竞争力，我们打算转换为公制管尺寸，这将:-导致一个全球系统-引导用户选择首选系统-降低复杂性消除库存重复

This specification covers stress relieved annealed electric resistance welded and cold-drawn single-wall high strength low alloy steel tubing intended for use in hydraulic pressure lines and in other applications requiring tubing of a quality suitable for bending, flaring, cold forming, and brazing.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 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 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 Test Methods for Hydraulic Fluid Power Connections. Cold forming the tube end connections in place of thermal processes such as brazing and welding 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 complexityEliminate inventory duplications