钻杆接头断裂失效分析  

Analysis of Drill Rod Sub Fracture Failure

作　　者：李晓晖[1] 李艳丽[1] 常吉星 王克虎[1] 孔令沪 满国祥 郑圆满 鲍华雷 程林[1] 朱立强[1] 

机构地区：[1]河北省地矿局国土资源勘查中心石家庄探矿机械厂,河北石家庄050081

出　　处：《中国煤炭地质》2015年第8期57-59,63,共4页Coal Geology of China

摘　　要：某钻孔临近煤矿采空区,采用正循环气动潜孔锤钻进,钻至110m时发生了钻具断裂事故。针对施工过程中出现的钻杆接头断裂失效情况,结合该孔的施工工况,通过对断口进行宏观分析及理化性能试验,结果表明:钻杆接头断裂的主要原因为岩屑上返过程中在钻具外径突变处发生沉积,造成钻杆接头与岩屑剧烈摩擦,造成接头严重磨损,同时产生高温,致使岩屑与接头基体金属熔结为一体,并使金相组织发生了奥氏体转变。高温奥氏体组织硬度、强度大大下降,而变形能力大大提高。在拉力、扭转等应力的作用下,最终在该处薄弱部位发生了过载断裂。A drilling tool fracture accident has been happened in a borehole near coalmine gob area in process of normal circulation pneumatic DTH drilling at depth 110 m. Considering the situation of drill rod sub fracture failure during the drilling, combined with borehole temporal operating mode, after fracture macroanalysis and physicochemical property testing have shown that the main causation of sub fracture is the deposition of rock cuttings on tool outside diameter abrupt changing position during the cuttings ascending,can cause severe friction between drill rod sub and cuttings, thus make subs seriously worn and torn. Mean while high temperature can make cuttings and sub matrix metal melting integrated, metallurgical structure austenitized. Hardness and strength of hyperthermal austenite have been descended, while deformability improving greatly. Under the stresses of tensile and torsion, finally the weakened area overloading fractured.

关 键 词：潜孔锤钻进 钻杆接头断裂 宏观分析 理化性能分析 

分 类 号：P634.8[天文地球—地质矿产勘探]