应用两种不同钻杆材料热处理到不同强度(105,135,150,165钢级)的真实应力-应变曲线, 分析了工程屈强比对形变硬化指数、真实断裂强度、均匀形变容量、静力韧度等的影响规律。结果表明: 工程屈强比与上述参数没有明显的对应关系, 不宜把工程屈强比作为高强度钻杆的一个硬性技术指标来要求, 良好的塑性是确保高强度钻杆安全使用的关键指标。采用特殊材料及严格热处理的150钢级钻杆, 虽然其工程屈强比较高, 但由于具有高塑性, 仍然具有良好的综合性能。

The influence of yield ratio on the strain-hardening exponent, the true fracture strength, the uniform plastic deformation capacity and static toughness was discussed by analyzing the true stress-strain curve of two materials with different yield strength (steel grades of 105, 135, 150, 165) by heat treatment. The results showed that the yield ratio had no significant correlation with above parameters. It cannot be strictly required in the high strength drill pipe, good ductility is a key technology index to ensure the safety of high strength drill pipe. For the drill pipe of steel grade 150 which manufactured by special material and strictly heat treatment, although it’s engineering yield ratio is quite high, it still has a good comprehensive performance because of its high plasticity.