4145H石油钻铤钢示波冲击性能研究

Study on Oscillography Impact Property of 4145H Drilling Collar(DC) Steel

对4145H钻铤钢纵向取样,研究了不同温度下的示波冲击特性。结果表明,取样钻铤的冲击功值满足《SYT5144-2007钻铤》和《API SPEC7》标准要求,并得出了4145H钻铤钢的冲击功随温度的降低而降低,起裂功与冲击功的比值随温度的降低而升高,裂纹扩展功以及裂纹扩展功与冲击功的比值随温度的降低而降低。在钻井工程中表现为常温下裂纹在钻铤中扩展速率较慢,钻铤不容易断;低温下裂纹在钻铤中扩展速率较快,钻铤更容易断。该研究成果为合理指导4145H钻铤的生产工艺和现场使用提供了依据,为分析4145H钻铤断裂机理提供了基础实验依据。

Longitudinal sampling method was adopted while 4145H DC steel was sampled.Oscillography impact properties were studied in four different temperatures.The research indicated that impact energy of sampled DC met the standard of'SYT5144-2007 Drilling Collar' and 'API SPEC7' in four different temperatures.With temperatures getting down,impact energy,crack propagation energy,and crack propagation energy/impact energy ratio decreased,cracking energy/impact energy ratio increased.In drilling,crack growth rate in DC was slow;the DC was not liable to fracture in normal temperature.On the contrary,crack growth rate was fast,as a result,the DC was easy to fracture in low temperature.The results provide reliable experiment resources for research on 4145H DC fracture.The research results provide reliable guidance for DC production and use in drilling and offer basic experimental evidence to the analysis of 4145H DC fracture mechanism.