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Abstract  

The hydrogen concentration for the reference material low-alloy steel was estimated using prompt gamma neutron activation analysis. The hydrogen concentration had a range of 0.91–1.14 mg/kg as measured by the prompt gamma activation method but the reference value was about 1.0 mg/kg as measured by the ICP/AES method. The relative error appeared to be 14% and the differences showed as the background by blank. The standard reference material (NIST SRM) was used for the analytical control.

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Abstract  

Determination of phosphorus in low-alloy steels by alpha-particle activation analysis has been studied in detail. After thick target yield curves of main interferences produced from the sample were measured as a function of alpha energy, the working standard for the present experiments was provided by applying the internal standard method coupled with the standard addition method under the most suitable bombarding conditions. Using the above working standard, it was demonstrated that the concentration of phosphorus in several low-alloy steels can be determined accurately and precisely by ordinary alphaparticle activation analysis.

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Abstract  

The paper deals with results of thermal analysis of low-alloyed chromium-molybdenum steel. The methods of analysis were dilatometry, differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The Ac1 and Ac3 temperatures of the steel samples measured by dilatometry and DTA during the heating period were in good agreement. Generated by cooling a martensitic structure first became apparent at 503 K. Tempering of the as-quenched samples showed the presence of the second tempering stage in the region between 473 and 573 K. At that stage heat capacity decreased from 0.48 to 0.32 J g-1 K-1, as a result of conversion of transition carbide due to heat consumption. After normalization of the as-quenched samples the heat capacity values were restored to between 0.42 and 0.47 J g-1 K-1 in the temperature range from 373 to 673 K.

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Abstract  

The viability of radiochemical neutron activation analysis as a method for certification of phosphorus in steels was tested by analysis of SRM low alloy steels. Preliminary results are generally in agreement with certified values. The limit of detection, as defined by Currie1, was determined to be 5 μg/kg.

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Abstract  

A reactor fast neutron activation analysis was used in combinationwith a simple pre-concentration procedure for determining silicon in someiron reference standard materials of Japan Iron and Steel Federation. Thesamples were dissolved with aqua regia and digested with perchloric or sulfuricacid. The precipitated silica was collected on a filter paper and irradiatedin a cadmium case with reactor fast neutrons. Silicon can be determined intool steel SKD6, low-alloy steel Nos 2 and 4 and silico-manganese samplesby a present method measuring 1,273.4 keV rays from 6.63-minute 29Alproduced by 29Si(n,p)29 Al reaction.

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Abstract  

Inhibited buffer-complexing ferrous citrate+citric acid solutions, 2.5<pH<3.5, at 363±5K, is used to dissolve a compact magnetite layer grown on low alloyed steel in a nuclear plant generator. The average rate of oxide dissolution is 40 m/h. Similarly, a compact duplex layer of magnetite covered by hematite formed on a carbon steel pipe of a classical heat exchanger dissolves in less than 10 h. The mean rate of metal uniform corrosion ranges between 1 and 9 mg/cm2 h depending on pH, inhibitors and citrate ion concentration.

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Abstract  

Nickel contents in different finished product alloys were determined using a k 0-based internal monostandard instrumental neutron activation analysis (IM-INAA) method. Five stainless steels (SS) and three high nickel alloys were analyzed by IM-INAA. BCS CRMs 225/1 (low alloy steel) and 466 (austenitic SS) and NIST SRM 247 (high Ni alloy) were analyzed to evaluate the accuracy of the method. The results of CRMs and SS were found to be in good agreement with certified or specified values. The Ni contents in the high nickel alloys were also determined by relative method of NAA for verification. Nickel contents in BCS CRM 466 and SS 316M were determined by UV–Visible spectrophotometry and the values were found to be in good agreement with IM-INAA results.

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Assessment of the Fe-Sn-Zn phase diagram at 450°C

Application to the batch galvanizing

Journal of Thermal Analysis and Calorimetry
Authors: Marie-Noelle Avettand-Fènoël, N. David, G. Reumont, J. Fiorani, M. Vilasi, and P. Perrot

Abstract  

The Fe-Sn-Zn system is of interest because Sn is one element added to the Zn galvanizing bath to overcome the drawbacks due to the presence of Si in semi-killed steels. This work has been undertaken with the aim to understand the tin effect on the microstructure and the layers growth in batch galvanized coatings on low alloyed steels. Various experimental techniques such as metallography, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX) are used in order to characterize the microstructure and the properties of such coatings elaborated in a zinc bath enriched with tin. Solidification phenomena and layers growth mechanisms during galvanization are explained by means of the ternary phase diagram Fe-Sn-Zn at 450�C. The Calphad method allows to obtain this phase diagram from the three optimized binary phase diagrams Fe-Sn, Fe-Zn and Sn-Zn and some experimental data inside the ternary Fe-Sn-Zn system.

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martensitic transformation in a medium-carbon low-alloy steel . Scripta Mater 60 : 1016 – 1019 10.1016/j.scriptamat.2009.02.042 . 18. Woodard , PR , Chandrasekar , S , Yang , HTY 1999

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– 305 , 1984 . 10.1007/BF02667333 [20] P. Maynier , B. Jungmann , and J. Dollet , “ Creusot-Loire system for the prediction of the mechanical properties of low alloy steel products ”, in Symposium on Hardenability Concepts with Applications to

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