The Acoustic Emission Signal Quality Analysis When The Material Of Bop Shell Tensile

ZG25CrNiMo has good toughness and high tensile strength,good anti-fatigue properties,used in oil industry in a wide range of applications.Because the bop is well control device of the core drilling equipment,used to control the pressure,realization near balance or owe balance pressure drilling,Improve the drilling speed and quality,Maximum found and protection reservoirs.Once the bop failure will cause a major economic loss,so for the bop equipment material characteristic is becoming more and more important.This paper first discusses the bop shell material in the bop shell on the application of present situation,this paper introduces the acoustic emission testing technology for the basic principle and the acoustic emission signal analysis and processing method.Acoustic emission instrument records the ZG25CrNiMo specimens in the failure process of the acoustic emission signal,the use of acoustic emission parameter analysis method and waveform analysis method ZG25CrNiMo defects of specimens of acoustic emission data for analysis,that in the process of material damage types and the characteristics of the present stage.The experimental results show that the tensile process failure mechanism of acoustic emission signal characteristics of influence is significant,the different stages of the signal frequency spectrum characteristics damage in different ways.Then analyses the bop shell material of acoustic emission characteristics and fracture type,and combining the finite element analysis method to the bop shell material for loading simulation,this paper analyzes the different kinds in standard specimens under pressure of mechanical properties,combining stress-strain curve,this paper discusses the different defects tensile fracture process,summarizes the bop shell material properties.From the tensile crack that process:The bop shell material ZG25CrNiMo fracture process may be divided into the crack tip is cracking stage,Crack the cracking stage,crack macro cracking stage,overall failure stages are four stages.The crack tip is cracking stage material shows good toughness and high tensile strength,Crack the cracking stage material shows good durability;Crack macroscopic crack stage materials represent strong fatigue toughness.With the tensile test,all represent each stage the fatigue fracture characteristics of the growing trend,for the performance of the acoustic emission high amplitude and the increase of high-energy signal.Fracture process each phase of the acoustic emission signal obvious,acoustic emission monitoring technology is ZG25CrNiMo acoustic emission signal characteristics of the effective means.