共查询到19条相似文献,搜索用时 62 毫秒
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王政富 《腐蚀科学与防护技术》1989,1(1):45-45
<正> 利用声发射技术监测了SM50B—Z_c海洋结构铜淬水及正火两种状态下,在空气和流动两种环境下的3.5%,NaC1水溶液(pH=8)的疲劳过程,并对这两种状态下的结果进行了比较。试验结果表明:声发射活动强烈地受热处理状态、组织取向、试样几何因素及介质条件的影响;强度愈高,声发射活动愈丰富。声发射参数与疲劳参数之间存在很好 相似文献
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对疲劳条件下6×19S+FC钢丝绳进行了声发射(AE)测试,结果表明,用AE事件的幅值,持续时间,能量和计数参数可综合表征断丝事件;在钢丝绳失效之前的60%处即能给出失效的AE预警,适当提取钢丝裂纺开裂的AE事件有利表征钢丝绳的总体损伤情况。 相似文献
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利用全数字声发射系统研究了轧制AZ31B 镁合金腐蚀疲劳过程中的声发射信号.结果表明,轧制AZ31B镁合金在NaCl溶液中的腐蚀疲劳过程主要存在4种声发射源,其中与腐蚀相关的两种信号分别对应于阳极溶解和阴极析氢,前者属于板平面内激励源,产生扩展波信号;后者属于板平面外激励源,产生弯曲波.与载荷相关的两种信号分别对应于塑性变形的连续型信号和裂纹扩展阶段高载荷阶段出现的裂纹扩展信号.腐蚀相关的声发射信号存在于整个疲劳过程,而塑性变形信号只发生在疲劳过程中特定的应力阶段. 相似文献
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采用声发射(acoustic emission,AE)技术对7N01铝合金单边缺口三点弯曲试样不同应力比、不同峰值载荷下疲劳裂纹扩展过程中声发射信号进行了监测,建立了裂纹扩展速率、声发射计数(count)与应力强度因子之间的关系.结果表明,大部分的声发射信号主要产生于疲劳循环载荷的低应力阶段,这主要是低应力阶段的声发射活动主要与裂纹尖端的塑性变形和裂纹闭合现象有关,声发射计数与应力强度因子之间呈指数增长的关系.基于所建立的声发射计数率与裂纹扩展速率的关系,可以预测疲劳损伤结构的剩余寿命. 相似文献
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WANG Zhengfu KE Wei Institute of Corrosion Protection of Metals Academia Sinica Shenyang ChinaZHU Zuming Insitute of Metal Research.Academia Sinica Shenyang China WANG Zhengfu Institute of Corrosion Protection of Metals Academia Sinica Shenyang China 《金属学报(英文版)》1990,3(10):241-245
Acoustic emisssion(AE)behavior during fatigue in either airer or 3.5% NaCl solution hasbeen studied for a structural steel(SM5OB-Zc)as quenched and normalized states.The ex-perimental results show that AE activity is strongly affected by the heat treatment and thecondition of environment.Some material constants about A E related with fatigue behaviorwere obtained and the AE sources in corrosion fatigue were discussed. 相似文献
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采用AE技术对超高强度钢37SiMnCrNiMoV在3.5%NaCl 溶液中的SCC行为进行研究.证明在裂纹的稳定扩展区内,裂纹是间歇,跳跃式的扩展.发现 腐蚀裂纹尖端的应力强度因子处于0.7KIC和0.23KIC时,平均每次声发射事件 对应的裂纹扩展量相近;应力强度因子处于035 KIC时,平均每次声发射事件对应 的裂纹扩展量较大;声发射事件的发生频率随应力水平的增加,有很大的增加.腐蚀裂纹扩 展的全过程存在两种不同的声发射信号.还证明了37SiMnCrNiMoV的应力腐蚀裂纹扩展过程 中,氢脆起着主要的作用.提出了计算腐蚀裂纹稳定扩展区内声发射事件累积数的公式. 相似文献
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PEI Hongxun YANG Jingjun KE Wei Institute of Corrosion Protection of Metals Academia Sinica Shenyang China PEI Hongxun Institute of Corrosion Protection of Metals Academia Sinica Shenyang China 《金属学报(英文版)》1989,2(9):167-171
The effects of environmental media,both in atmosphere and in 3.5% NaCl aqueous solution,on the growth of short cracks in comparison with the long ones have been investigated underfatigue loading on the specimens of single-edge crack about 0.05—0.15 mm for A537CLIsteel.The growth rate of short cracks is faster than those of long ones around the threshohtstress intensity.The threshold stress intensity for short crack growth decreases with de-creasing crack length.The acceleration effect of the salt water,as compared with atmosphereenvironment,on the growth of short cracks under fatigue is much greater than that on thegrowth of long cracks. 相似文献
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研究LY12CZ,30CrMnSiA两种飞机主要承力结构材料制成的机械紧固连接件在不同环境中的DFR值。 相似文献
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用声发射对某液体推进剂贮罐出现的焊缝应力腐蚀进行了研究.结果表明,声发射技术可以用来对压力容器的应力腐蚀过程进行监控;根据声发射信号强度及其变化可以准确判断设备的运行状况,定量确定压力容器的服役年限. 相似文献
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ZHOU Zhao JI Shichen HU Zhuangqi SHI Changxu 《金属学报(英文版)》1989,2(2):137-142
Study of the solidification process of both Al-Si and Al-Cu alloys proved the presence ofacoustic emission phenomena.Two peaks of count rate have been observed.The total countsof both peaks increase with the increasing hydrogen content of the alloy.The mechanism ofproducing the acoustic emission has been discussed.At the same time,results obtained by oth-er techniques strongly support the good correlation between the acoustic emission andhydrogen releasing during solidification.The bubble nucleation between dendrite arms is themain cause of the first peak,while the fracture of the bridge connecting the interdendrites atthe later stage of solidification is the main cause of the second peak.It is probably due to thehydrogen evolution and accumulation to create high pressure in the interdendritie region. 相似文献