钻杆接头的技术标准与用钢及热处理工艺

针对钻杆接头生产中的一些问题，讨论了钻杆接头的强度、硬度和韧性指标，材料选择及冶金质量，热处理中的回火脆性、淬火介质等，提出：（1）除对钻杆接头室温韧性提出要求外，还应考虑低温韧性。对内螺纹接头应提出横向韧性要求。建议接头韧性采用APISpec5D中对钻杆管体规定的数值。认为APISpec7中接头强度和硬度要求不对应，建议最低硬度由285HB改为295HB；（2）钻杆接头用钢应兼顾机械性能和可焊性。在保证淬透性的情况下应适当降低碳含量。为保证韧性，建议采用纯净钢；（3）接头用钢热处理对易产生回火脆，通过重新调质及回火后快冷可解决这一问题。为进一步提高接头性能，可采用水溶性淬火介质。

Specification and material selection and heattreatment process for tool joints

The authors discuss the strength , hardness and toughness requirements, material selection and heattreatment for tool joints, and suggest: (1) the toughness be specified at both room and low temperature, and for the box end of tool joints,transverse impact toughness be specified as stipulated in API Spec 5D, and the minimum hardness of tool joints be HB295 instead of HB285; (2) both mechanical properties and weldability be taken into consideration in the selection of tool joints material, and clean steel be used to ensure good toughness; (3) rapid cooing be carried out to avoid temper brittlement of steel for tool joints, and quenching medium be improved to ensure tool joints for good comprehensive properties.