Research on Increasing the Nitrogen Removal Efficiency by Changing the Secondary Treatment Parameters

2014 ◽  
Vol 216 ◽  
pp. 267-272 ◽  
Author(s):  
Erika Ardelean ◽  
Marius Ardelean ◽  
Teodor Hepuț ◽  
Florin Drăgoi

The existence of gases in the solid metals (hydrogen and nitrogen) assumes the presence of these gases in metals even before solidification, respectively in the elaboration, secondary treatment and casting phases. Usually, great amounts of gases dissolved in steels can be detected, between 3.5-8ppm for hydrogen and 0.02-0.03% for nitrogen, respectively. There are also cases when the purpose is to alloy with nitrogen, this being the case of austenitic stainless steels where the nitrogen content can reach 0.5% using ferrochromium or ferromanganese alloyed with nitrogen in 3-5.5 %. The main method of removing these gases is bubbling with inert gases and /or treating the steel in a vacuum facility. The paper presents a study regarding increasing the removal efficiency of nitrogen from the liquid steel by changing the bubbling parameters (flow, pressure, duration) but also the basicity of the refining slag. The equations of the regression surface and the identified fields are of a real help for the technologists, allowing quick decisions but they are also important for the quality of the metallic products [.

2012 ◽  
Vol 224 ◽  
pp. 142-145
Author(s):  
Jozef Jurko ◽  
Anton Panda ◽  
Marcel Behún

This paper presents the conclusions of machinability tests on a XCr18Ni8 stainless steel. The content of this article also focuses on the analysis of selected basic indicators of steel machinability: quality of the processed surface. The results of the article are conclusions for working theory and practice for drillng of austenitic stainless steels. Based on the cutting tests, cutting speeds of 40 to 60 m/min, feed rate of 0.04 to 1.2 mm and screw drill carbide monolite.


2012 ◽  
Vol 500 ◽  
pp. 9-13
Author(s):  
Mário Gajdoš ◽  
Andrej Berdis ◽  
Ján Gecák ◽  
Milan Mičko ◽  
Tadeaš Kurilovský

Precise and reliable information on the machinability of a material before it enters the machining process is a necessity, and hypotheses must be tested through verification of actual methods. This article presents conclusions of machinability tests on a new austenitic stainless steels X2Cr12Ni12MoTiN and describes appropriate parameters for the cutting zone during the process of turning. The content of this article also focuses on the analysis of selected basic indicators of steel machinability: quality of the processed surface. The results of the article are conclusions for working theory and practice for turning of austenitic stainless steels. Based on the cutting tests, cutting speeds of 80 to 200 m/min, feed rate of 0.05 to 0.2 mm and solid carbide insert WNMG 080404-NF.


Author(s):  
Mahmood Pakshir ◽  
Sanam Atashin ◽  
Arash Yazdani

In this research the synergistic effect of environmental factors on corrosion rate of austenitic stainless steels 304 and 316 has been assessed. The behavior and resistance of these alloys are studied in aerated synthetic seawater, using potentiodynamic polarization scan. The salinity, velocity, pH and temperature are the considered parameters. To study the individual and interactive contribution percentage of parameters on changing the average value of corrosion rate, a quantitative full two-level factorial experimental design method is applied. Beside this quantitative analysis, qualitative analysis has been used to predict the variation direction. By means of these two analyses we can predict the magnitude and quality of each parameter’s effect. This research has a potential in prediction of alloys’ behavior, which is really valuable in marine engineering designs.


2011 ◽  
Vol 291-294 ◽  
pp. 2987-2990 ◽  
Author(s):  
Jozef Jurko

This paper presents the conclusions of machinability tests on a new austenitic stainless steel X6Cr16Ni10MoTiN, which applicated in food processing industry, and describes important concurrent parameters for the cutting zone during the process of turning. The content of this article also focuses on the analysis of selected basic indicators of steel machinability: quality of the processed surface. The results of the article are conclusions for working theory and practice for turning of austenitic stainless steels. Based on the cutting tests, cutting speeds of 60 to 220 m/min, feed rate of 0.06 to 1.2 mm and solid carbide indexable insert CNMG 160404-MF.


2020 ◽  
Vol 854 ◽  
pp. 16-22 ◽  
Author(s):  
Artem D. Davydov ◽  
Olga O. Erokhina ◽  
Sergey Vladimirovich Ryaboshuk ◽  
Pavel Valer'evich Kovalev

Austenitic stainless steels are widely used in industry. Increased requirements for the quality of products from these steel grades, the difficulties associated with the implementation of technological processes, as well as the high cost of steel, determine the necessity to assess probable causes of defects. This article presents an analysis of the influence of main process parameters on the quality of products from the grade 08X18H10T steel. Based on the results of statistical analysis and thermodynamic modeling, it was concluded that the increased content of titanium and nitrogen affects the quality of products, which is caused by the formation of titanium carbonitrides in the process of steel solidification.


Author(s):  
J. J. Laidler ◽  
B. Mastel

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.


Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D. Matlock

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.


The Eye ◽  
2020 ◽  
Vol 22 (130) ◽  
pp. 36-43
Author(s):  
Gulnara Andrienko

Corneal topography is the main method for assessing the regularity of the surface of the cornea. Corneal irregularity leads to a deterioration in its refractive properties and a decrease in the quality of vision. Learning the basics of corneal topography will help determine the choice of a color map for a specific situation, as well as understand and analyze the data associated with these maps. This article describes the main types of topographic maps, various patterns of corneal shape in normal and pathological conditions and how to use the data obtained to design and fit contact lenses. Despite the fact that images may vary depending on topographers used, the information presented in this article is universal.


2015 ◽  
Vol 57 (7-8) ◽  
pp. 597-601 ◽  
Author(s):  
Peeraya Pipatnukun ◽  
Panyawat Wangyao ◽  
Gobboon Lothongkum

Alloy Digest ◽  
2011 ◽  
Vol 60 (1) ◽  

Abstract EPRI P87 is a MMA electrode designed for dissimilation joints between austenitic stainless steels (i.e. 304H) and a creep resisting CrMo alloy (i.e. P91). This datasheet provides information on composition and tensile properties as well as fracture toughness. It also includes information on joining. Filing Code: Ni-685. Producer or source: Metrode Products Ltd.


Sign in / Sign up

Export Citation Format

Share Document