共查询到20条相似文献,搜索用时 343 毫秒
1.
分析了电渣重熔钢板探伤不合格的机理,对缺陷部位进行取样分析,通过低倍检查和微观分析,指出缺陷产生的原因,提出相应的改进措置,同时提高和优化超声波探伤检查方法,保证电渣重熔钢内部探伤质量合格。 相似文献
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本文介绍了SUJ2棒材近表面缺陷的探伤方法,探讨了横波探伤技术在棒材近表面缺陷探伤工艺中的有关入射角、探测范围、水层等技术参数的数学表达式,经验证采用横波探伤技术对棒材近表面缺陷的探伤是一项有效的探伤方法,满足了SUJ2棒材质量控制的要求. 相似文献
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阐述了无缝钢管在轧制过程中产生的表面和内部缺陷的两种探伤方法,即涡流探伤和漏磁探伤。介绍了两种方法的基本原理,分析比较它们在无缝钢管探伤中的应用特点。 相似文献
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本文针对生产低合金中厚钢板出现超声波探伤缺陷的现象,分析探讨缺陷的产生原因及形成机理。从而采取有效措施,防止钢板缺陷的产生,提高探伤合格率。 相似文献
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济钢针对钢板探伤综合合格率偏低的问题,对探伤不合的原因进行了分析。统计表明,缺陷部位主要集中在钢板的头部和边部,占统计量的73.74%,主要是长条状和点状密集型缺陷;缺陷类型包括分层、偏析、疏松、白点及夹杂物,并分析了其探伤波形。通过严格控制钢中S和夹杂物含量、改善连铸坯内部质量、保证加热时间、增加单道次压下量、强化热处理的挽救措施,使探伤合格率稳定在99.0%以上。 相似文献
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本文主要介绍了压煮器管座角焊缝的超声波探伤中,应选用的探伤工艺、探伤方法和步骤,通过对探伤波形的分析,来进行缺陷的判断,以保证压煮器管座角焊缝的质量。 相似文献
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用压力容器对接焊缝超声波探伤过程中。在一定条件下会产生变型干扰波,很容易被误判为缺陷波。通过分析变型波的产生机理和总结实际探伤经验,明确了这种假设缺陷回渡产生的原因及特点。对压力容器焊缝超声波探伤有参考意义。 相似文献
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Takehiko Watanabe Atsushi Yanagisawa Shiro Sunaga 《Metallurgical and Materials Transactions A》2003,34(5):1107-1111
In the ultrasonic welding process, it is well known that the bonding between both faying surfaces can be completed by ultrasonically
agitating them for a short duration, such as 1 second, at room temperature. In this study, the atomic interaction (chemical
bonding) across the interface between aluminum and an alumina ceramic, which was ultrasonically bonded using an ultrasonic
pulse that lasted for a short time of 1.5 seconds, was analyzed by means of Auger electron spectroscopy (AES) in order to
clarify whether chemical bonding can be achieved across the interface. The Auger spectra analyses results suggest that chemical
bonding exists between Al and O across the aluminum/alumina interface bonded ultrasonically for short duration of 1.5 seconds,
and that aluminum was chemically bonded to alumina. 相似文献
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Y. Ijiri P. K. Liaw B. J. Taszarek S. Frohlich M. N. Gungor 《Metallurgical and Materials Transactions A》1988,19(9):2215-2224
Interfaces of the babbitt metal-bronze composite were examined ultrasonically and were fractured using the Chalmers test method.
It was found that the ultrasonic results correlated with the bond strength, the ductility, and the degree of bonding at the
tested interface. Specifically, high ultrasonic reflection percentages were associated with low bond strength, low ductility,
and low percentages of bonded regions. The fracture mechanism in the bonded area of the babbitt-bronze interface is related
to the presence of the intermetallic compound, Cu6Sn5, at the interface. It is suggested that the non-destructive ultrasonic technique can detect the bond integrity of babbitted
metals. 相似文献
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采用低共熔溶剂为浸出剂,进行从含锌尘泥超声浸锌试验。分析了超声功率、温度、液固比、搅拌速率、反应时间等对锌浸出率的影响。结果表明:在超声功率90 W、温度40 ℃、液固比7 mL/g、转速250 r/min、浸出时间80 min条件下,锌超声浸出率可达98.48%。超声强化浸出过程受混合固体产物层的控制,表观活化能为11.23 kJ/mol。 相似文献
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Carboxymethylglucan (CMG) with ultrasonically lowered molecular weight (0.89 x 10(5)) was administered either intraperitoneally, intravenously or orally prior to cyclophosphamide (CP) injection and its effect on the frequency of micronuclei in mouse bone marrow was evaluated. Both parenteral (intraperitoneal and intravenous) and oral administration of CMG decreased the clastogenic effect of CP. The protective effect induced by intravenous and intraperitoneal administration was concentration-dependent, with a higher decrease achieved by 200 mg/kg than by 100 mg/kg body weight. With the lower dose of CMG a 2-h interval was necessary between intravenous CMG administration and CP injection. Oral pretreatment of mice with CMG decreased statistically significantly the frequency of micronuclei in polychromatic erythrocytes of the bone marrow. The fact that ultrasonically depolymerized CMG was effective also on oral administration is indicative of the passage of smaller CMG molecules through the wall of the gastrointestinal tract. 相似文献
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D Stanojevi? R S?epanovi? R Perunovi? V Zivanovi? P Stevanovi? 《Canadian Metallurgical Quarterly》1998,126(5-6):214-216
In order to obtain good results in laparoscopic surgery the surgeon should be well trained and experienced and the equipment perfect. The recent innovation in laparoscopic surgery is the ultrasonically activated scalpel. Scissors make the working part of scalpel with one hand vibrating 55,000 Hz in a second. The effect reflects in braking hydrogen links and denaturation of proteins in instant haemostasis and coagulation in blood vessels, and there is no need of tying them up. Practically, there is no damaging of the surrounding tissues. The technique is easy to use. When performing laparoscopic vaginal hysterectomy and adnexectomy the ligamentum infundibulopelvicum and ligamentum rotundum are cut, and there the blood vessels are not thicker than 3 millimeters. As these ligaments are easy to reach with ultrasonically activated scalpel, we can say that this instrument is the ideal option for laparoscopic vaginal hysterectomy. 相似文献
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HV Jordaan 《Canadian Metallurgical Quarterly》1976,50(30):1166-1170
Data on the biparietal diameter (BPD), determined ultrasonically, of the full-term South African Negroid fetus are presented. Population differences in the absolute value of the BPD and the linear regression of birth weight on the biparietal dimension are emphasised. The possible biological explanations for these differences are discussed. 相似文献
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Ronald A. Cohen Frank J. Bachner Robert E. McMahon 《Metallurgical and Materials Transactions B》1971,2(3):723-727
A single metal system for beam-leaded chips, substrates and crossovers has been shown to be feasible using aluminum. Beams were formed on both ceramic substrates with holes tented with Riston (a sheet photoresist) and on silicon wafers by vacuum evaporation of aluminum from multiple tungsten filaments, and subsequent delineation and etching using photolithographic techniques. The chips with beams were separated from the wafer by anisotropic etching, and the tenting material removed from the ceramic by dissolution in appropriate solvents or an oxygen plasma. Beams were formed on polyimide sheet by photolithographically etching an adhesiveless laminate of aluminum on polyimide. Actual working samples have been fabricated of aluminum beam leads on ceramic and plastic substrates, aluminum beam leaded crossovers on ceramic, aluminum crossovers on plastic using multilayers and aluminum beam leaded silicon chips. Standard integrated circuit chips have been ultrasonically bonded into these substrates and the beam leaded chips have been ultrasonically bonded to an aluminum coated substrate. Environmental physical tests have shown the beam leads and crossovers to be rugged. 相似文献
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S Omi K Yokoyama H Yoshikawa K Takahashi K Sato 《Canadian Metallurgical Quarterly》1996,45(12):1507-1510
Spinal anesthesia with 3 ml of 2% plain lidocaine was administered to 10 women for ultrasonically guided vaginal oocyte retrieval. Spread of anesthesia was assessed by skin vasodilatation, change of skin texture, loss of goose flesh reflex, and loss of cold as well as pin-prick sensation, and we studied time to complete motor block, time to two-segment regression, time to full motor and sensory recovery, ambulation time, haemodynamic parameters, and postoperative complications. The highest sensory block assessed by pin-prick was up to Th 8.3 +/- 3.4 10 min following spinal anesthesia. All patients had complete motor block and this was achieved at 9.0 +/- 1.7 min. Times to two-segment regression, full motor and sensory recovery, and ambulation were 84.5 +/- 31.0, 147.5 +/- 24.7, 176.5 +/- 23.2, and 203.3 +/- 50.0 min, respectively. No serious side effects were observed during the operation and postoperatively. We concluded that 3 ml of 2% plain lidocaine provided adequate spinal anesthesia for ultrasonically guided vaginal oocyte retrieval. 相似文献
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In contrast to former opinions detection of genetic disorders in early multiple pregnancy is possible by advanced techniques of amniocentesis Prenatal diagnosis has been performed in a twin pregnancy of an 41 years old patient by two ultrasonically guided amniocenteses. Injection of Indigo carmin after the first puncture showed two separate amnion cavities. Postpartal findings proved prenatal diagnosis. 相似文献