NCS Testing Technology Co.

Beijing, China

NCS Testing Technology Co.

Beijing, China

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Li X.,Zhenjiang Siyang Special Metal Material Manufacture Co. | Bian J.,Zhenjiang Siyang Special Metal Material Manufacture Co. | Liu P.,NCS Testing Technology Co.
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2015

Microstructure of copper alloy ingot was analyzed by ultrasonic testing combined with metallographic observation. The results reveal that two kinds of shrinkage porosities easily occurs in the forging parts, and they demonstrate different ultrasonic waveform characteristics and microscopic form, which provides effective information to determine the shrinkage porosities for subsequent ultrasonic testing. By analyzing the origination of two kinds of shrinkage porosities, the defects in copper alloy ingot casting were eliminated by modifying casting process, and the yield rate of the copper alloy casting was improved greatly. ©, 2015, Journal Office of Special Casting and Nonferrous Alloys. All right reserved.


Zhou D.Q.,University of Science and Technology Beijing | Zhao W.X.,University of Science and Technology Beijing | Mao H.H.,KTH Royal Institute of Technology | Hu Y.X.,University of Science and Technology Beijing | And 3 more authors.
Materials Science and Engineering A | Year: 2015

In this paper, the dynamic evolution of precipitates and its influence on the high-temperature mechanical properties of newly developed AFA steels were systematically investigated. At 1023K or above, three main types of precipitates, i.e., the B2-NiAl, Laves-Fe2Nb, and δ/σ phases, were formed in the base steel, and the major strengthening medium is Laves-Fe2Nb, which coarsened quickly, leading to undesirable creep properties. Phase competition between the most effective strengthening NbC nanosized precipitates and the Laves-Fe2Nb phase was analyzed, and it was found that adjusting the Nb/C ratio in the steels could enable the precipitation of highly stable, fine NbC particles. In addition, the formation of detrimental σ phases could be suppressed by lowering the Mo and Si content in the alloy. Eventually, a new type of AFA steel consisting of a high density of nanosized NbC particles homogeneously dispersed in the austenitic matrix was successfully developed, and significant enhancement in the creep resistance was achieved due to the effective strengthening resulting from the tiny secondary NbC particles. © 2014 Elsevier B.V.


Li X.-H.,Shandong Xiangguang Copper Co. | Wan S.,Shandong Xiangguang Copper Co. | Liu Z.-J.,Shandong Liaocheng Entry Exit Inspection and Quarantine Bureau | Guo F.-F.,NCS Testing Technology Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2016

The content range of calibration curve was broadened using certified reference material of copper concentrate and adding spectral-purity substance or standard solution of single element. The sample was prepared by fusion method. The content of copper, lead, chromium, arsenic, silver, antimony, bismuth, nickel, iron and aluminum in copper concentrate was determined by wavelength dispersive X-ray fluorescence spectrometry(XRF). The fusion conditions were obtained by experiments and listed as follows: the lithium tetraborate-lithium metaborate mixed flux (m:m=33:67) was used; the dilution ratio was 1:20; the pre-oxidization time was 5 min; the pre-oxidization temperature was 700℃; the fusion time was 10 min; the fusion temperature was 1 000-1 050℃ ; the silicon dioxide was used as glassing reagent; 3-4 drops of 500 g/L lithium bromide solution was used as releasing reagent. The interference of coexisting elements and spectral overlapping could be corrected by theoretical influence coefficient method. The detection limits were between 12 μg/g and 156 μg/g. The precision test was conducted using one copper concentrate sample. The relative standard deviations (RSD, n=11) of determination results of testing elements were between 0.19% and 11.3%. The found results of three actual copper concentrate samples were consistent with those obtained by standard analysis method. The proposed method could meet the requirements of rapid analysis of copper concentrate samples. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.


Wan S.,Shandong Xiangguang Copper Co. | Guo F.-F.,NCS Testing Technology Co. | Li X.-H.,Shandong Xiangguang Copper Co. | Liu Z.-J.,Shandong Liaocheng Entry Exit Inspection and Quarantine Bureau
Yejin Fenxi/Metallurgical Analysis | Year: 2016

0.040 0 g of sample was transferred into crucible (which had been burned before) containing 0.3 g of vanadium pentoxide flux. Then, 0.2 g of tin particles was added followed by covering with 0.15 g of vanadium pentoxide flux and 1.4 g of tungsten particles. The calibration curves were prepared with potassium sulfate. Thus, a determination method of sulpfur with mass fraction of 5.00%-40.00% in copper concentrate was established by high frequency combustion infrared absorption method. The results showed that the calibration curves could be prepared with integral area as horizontal ordinate and absolute sulfur content as vertical coordinate. The linear equation of calibration curve was Y=37.02X-1.52 with linear correlation coefficient of R=0.999 8. The detection limit of method was 0.017%. The proposed method was applied to the determination of sulfur content in copper concentrate actual sample. The results were consistent with those obtained by gravimetric method or combustion-titration method. The certified reference material of copper concentrate was determined according to the experimental method, and the results were consistent with the certified values. The actual samples and certified reference material of copper concentrate were determined for six times. The relative standard deviations (RSD, n=6) were between 0.41% and 0.72%. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.


Chen J.Y.,Beijing Institute of Technology | Li Q.,Beijing Institute of Technology | Li J.,NCS Testing Technology Co. | Tang X.,Beijing Institute of Technology | Xiao C.B.,Beijing Institute of Technology
Materials Science Forum | Year: 2016

The effects of Co additions on the evolution of γ’ precipitates and topologically close-packed (TCP) phases during thermal exposure at 950 °C were investigated for two Ni-based single crystal superalloys with 7.9 wt.% Co and 9.1 wt.% Co. The results indicated that the γ′ morphology was not affected by Co content, whereas γ′ volume fraction decreased and precipitate size increased due to lower Co addition after standard heat treatment. The coarsening of γ′ precipitates in both alloys was controlled by diffusion. The γ′ coarsening rate increased, while the stability of γ′ volume fraction decreased due to lower level of Co addition during 950 °C thermal exposure because more Co addition suppressed the diffusion process. High Co addition promoted the formation of μ phase after thermal exposure at 950 °C for 1000 h due to higher γ′ volume fraction, more stable γ′ volume fraction and higher electron vacancy number. The experimental results of μ phase precipitation showed good agreement with thermodynamic calculation by JMatPro. © 2016 Trans Tech Publications, Switzerland.


Shi Y.,NCS Testing Technology Co.
Key Engineering Materials | Year: 2016

A combination study of magnetic and magnetostrictive properties in directionally cast and differently heat-treated Fe-20Ga(at.%) samples has been carried out at room temperature. Slow cooling leads to an increase in the occupation of [200] easy magnetic axes; however, a structural ordering of Ga atoms into a metastable D03 phase decreasesthe saturation magnetostriction (λs) and the saturation magnetization (Ms), and increases coercivity (Hc). Our results confirm the contribution of D03 ordering to magnetic and magnetostrictive properties due to their pinning effects against magnetic domain wall motions. As compared to slow cooling, water quenching suppresses the formation of metastable (D03) or stable (L12) ordered phases and preserves the A2 single phase structure down to room temperature, leading to enhanced magnetostriction and magnetization. © 2016 Trans Tech Publications, Switzerland.


Zhao H.-Y.,NCS Testing Technology Co. | Qi R.,NCS Testing Technology Co. | Hou Y.-X.,NCS Testing Technology Co. | Zhou X.-X.,NCS Testing Technology Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2016

The sample was dissolved by hydrochloric acid and nitric acid. After removing carbon by perchloric acid fume, the content of arsenic, copper and zinc in lead concentrate was determined in 20% (V/V) acid medium by inductively coupled plasma atomic emission spectrometry (ICP-AES) using As 188.980 nm, Cu 327.395 nm and Zn 328.233 nm as analytical lines. The results showed that the determination results of arsenic, copper and zinc were not significantly affected by matrix effect. The calibration curves were prepared by lead-free matrix matching method. The linear correlation coefficients of calibration curves were higher than 0.9998. The detection limit of arsenic, copper and zinc was 0.0327 mg/L, 0.0240 mg/L and 0.130 mg/L, respectively. The arsenic, copper and zinc in lead concentrate standard sample were determined according to the experimental method. The relative standard deviations (RSD, n=7) were between 0.64% and 1.1%. The found results were consistent with the certified values and those obtained by alkali fusion ICP-AES. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.


Luo Q.-H.,NCS Testing Technology Co. | Li D.-L.,NCS Testing Technology Co. | Fan Y.-Z.,NCS Testing Technology Co. | Wang H.-Z.,NCS Testing Technology Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2015

Original position statistic distribution analysis (OPA) technique was applied to study element segregation in cross-section of stainless steel continuous casting (CC) slab. Combined with the macrostructure morphology, the rule of statistical distribution of each element was characterized quantitatively. A cyclic annular segregation band, which corresponded with the white band in the macrostructure morphology and caused by electromagnetic stirring, was in the edge of cross-section of CC slab. In this segregation band, C, Si and Ti were negative segregation, Ca and Al were positive segregation. Another segregation band in the inner side of the white band had opposite distributions with the white band, which corresponded with the junction of isometric crystal and columnar crystal. The maximum segregation points of C, S and Ti concentrated in the central part of cross-section, the maximum segregation points of Si, Mn, P and Ca distributed near the white band and the maximum segregation points of Al distributed dispersively. Ca, Al and Ti were the main segregation elements of the continuous slab. Maximum segregation degrees and statistic segregation degrees of Ca, Al and Ti were both higher and the homogeneities were relatively poor. ©, 2015, Central Iron and Steel Research Institute. All right reserved.


Hou H.-X.,NCS Testing Technology Co. | Guo F.-F.,NCS Testing Technology Co. | Yang Q.-Q.,NCS Testing Technology Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2015

The experimental conditions for the determination of nitrogen content in recarburizer by pulse heating inert gas fusion-thermal conductivity method were optimized. It was found that the recarburizer samples must be dried in oven at 100-110 ℃ after preparation. Moreover, the samples after grinding should be treated with 120 μm sieve. The optimized analytical power of instrument was 4.5 kW. The nickel foil should be used as flux to fully release the nitrogen in sample. The standard coal sample with similar composition and structure to the recarburizer was used to plot the calibration curve of nitrogen. The linear correlation coefficient was R2=0.993.The detection limit of nitrogen was 0.000 06%. The low limit of determination was 0.000 2%. The precision test of recarburizer sample was conducted, and the relative standard deviation (RSD, n=7) was not more than 3.4%. The actual samples were determined by the proposed method, and the found results were consistent with those obtained by pulse fusion-time of flight mass spectrometry. © 2015, Central Iron and Steel Research Institute. All right reserved.


Hou Y.-X.,NCS Testing Technology Co. | Liu Q.-B.,NCS Testing Technology Co. | Hu J.-Y.,NCS Testing Technology Co. | Meng Z.-J.,NCS Testing Technology Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2015

The key to determination of impurity elements in tin powder was to eliminate the matrix effect of tin powder because of its serious memory effect in mass spectrometer. After the tin powder sample was dissolved with aqua regia by heating, 4 mL of hydrobromic acid-hydrochloric acid mixture (V/V=1:1) was added, and tin was removed by volatilization at 110℃ for about 0.5 h. The volatilization process was repeated for three times in all. Then, the content of lead, indium, manganese and zinc in sample was determined by aerosol dilution-inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that the amount of residual tin in sample solution was less than 0.04% of sample mass after the pretreatment of tin powder. The optimized instrumental parameters were listed as follows: carrier gas flow rate of 0.60 L/min, and dilution gas flow rate of 0.42 L/min. The proposed method was applied to the determination of lead, indium, manganese and zinc in actual tin powder sample. The relative standard deviations (RSD) were in range of 3.6%-4.7%, and the recoveries were between 89% and 110%. The contents of four elements above in one tin powder sample were determined by the experimental method and inductively coupled plasma atomic emission spectrometry, respectively, and the results were basically consistent. © 2015, Central Iron and Steel Research Institute. All right reserved.

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