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为了研究不同传感器布置方式的声发射信号特性,以断铅实验模拟声发射源,采用光学显微镜(OM)、声发射检测仪测试了304不锈钢的显微组织与声信号特性参数。结果表明,不同截面的304不锈钢显微组织主要含有α’马氏体和奥氏体γ相,γ和α’晶粒平均尺寸大多低于20μm,所占比例超过75%,大于40μm的晶粒相对较少,纵截面显微组织相对致密;正方形布置传感器时,4个位置的声发射信号特性参数值波动较小,但等腰三角形、直线形布置传感器时,距模拟声发射源近的声活动相对较强;且随该距离增加,声信号特性参数减少幅度较大。
In order to study the acoustic emission signal characteristics of different sensor arrangements, the lead-free experiment was used to simulate the acoustic emission sources. The optical microscopy (OM) and acoustic emission detector were used to test the microstructures and acoustic signal characteristics of 304 stainless steel. The results show that the microstructures of 304 stainless steel with different cross sections mainly contain α ’martensite and austenite γ phase, and the average size of γ and α’ grains is mostly below 20μm, accounting for more than 75% and more than 40μm Relatively less longitudinal section of the microstructure is relatively dense; Square sensor, the four positions of the acoustic emission signal characteristics of small fluctuations in the value, but the isosceles triangle, linear sensor arrangement, the distance from the simulated acoustic emission source near the sound The activity is relatively strong; and as the distance increases, the acoustic signal characteristic parameters decrease greatly.