Effect of NaCl and CaCl2 additives on NaNO3 bath nitriding of steel

Lee, Min-ku; Kim, Dong-sam; Kim, Sung‐Chul; Han, Sang-Won; Kim, In-Soo; Lee, Dong Nyung

doi:10.1016/j.msea.2009.09.021

Cited by 14 publications

(19 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, a small peak ranging from 2100 to 2200 cm −1 is found among the g-C 3 N 4 -S x and g-C 3 N 4 -P x series and enhances with the increase of NaNO 3 or KNO 3 amount, assigning to the presence of C N triple bonds [28,30]. It was reported that NaNO 3 started to decompose over 500 • C to generate molecular oxygen and nitrogen oxides [24]. The generated nitrogen oxides were suspected to role as oxidation reagents to attack and subsequently broke the tri-s-triazine units to produce C N moietycontaining fragments.…”

Section: Ft-ir Spectramentioning

confidence: 99%

See 1 more Smart Citation

A facile modification of g-C3N4 with enhanced photocatalytic activity for degradation of methylene blue

Chang

Xie

et al. 2013

Applied Surface Science

186

View full text Add to dashboard Cite

a b s t r a c tIn this investigation, a facile modification of g-C 3 N 4 through co-pyrolysis of melamine and sodium nitrate or potassium nitrate was reported and the as-synthesized samples were characterized by a collection of techniques, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, nitrogen adsorption-desorption, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and elemental analysis. Based upon the analysis, we speculated that the g-C 3 N 4 framework was partially destroyed to produce cyano-containing fragments, which resulted into the variation of physical and optical properties, further affecting the adsorption and photocatalytic performance of g-C 3 N 4 on the dye methylene blue. Furthermore, we found that nitrate anions rather than sodium or potassium ions had important effect on the structure and photocatalytic performance of g-C 3 N 4 . In addition, the photocatalysis mechanism and reusability test were also investigated and discussed in the study.

show abstract

Section: Ft-ir Spectramentioning

confidence: 99%

“…It was reported that sodium nitrate could decompose to nitrogen oxides and gaseous oxygen over 500 • C [24]. The resultant nitrogen oxides might attack the tri-s-triazine at high temperature as oxidants to alter the framework of g-C 3 N 4 .…”

Section: Introductionmentioning

confidence: 99%

A facile modification of g-C3N4 with enhanced photocatalytic activity for degradation of methylene blue

Chang

Xie

et al. 2013

Applied Surface Science

186

View full text Add to dashboard Cite

show abstract

“…The proposal to develop nitriding with nitrate is considered a promising method for the input of nitrogen in iron and steel, although the surface oxidation cannot be avoided. The oxidation of the surface can cause not only a slight loss of steel, but also a reduction in the rate of nitriding, because of the surface layer of oxide that hinders the nitrogen sources that reach the steel (LEE et al, 2010).…”

Section: Theoretical Frameworkmentioning

confidence: 99%

“…Studies on the use of non-toxic salts in the nitriding process indicate satisfactory results, when compared to salt baths containing cyanides. Among the properties analyzed, most of them compare the superficial hardness in relation to the conventional process and also mechanical properties (BALIKCI;YAMAN, 2011;FUNATANI, 2004;LEE et al, 2010;SHEN;OH;LEE, 2005). The salt used, the parameters of time and temperature are described, but there is a lack of information about the visual aspect of the layer and the composition of the baths.…”

Section: Introductionmentioning

confidence: 99%

Nitriding in low carbon steels using non-toxic salt baths

Bonow

Maciel

Zimmer

et al. 2019

View full text Add to dashboard Cite

Resumo O objetivo deste artigo é desenvolver um método de nitretação em banhos de sais atóxicos, utilizando nitrato de potássio (KNO3) e nitrito de sódio (NaNO2), bem como, avaliar a dureza e o aspecto visual da camada superficial de um aço com 0,2% de carbono, vislumbrando uma alternativa que busca redução no impacto ambiental, gerado pelo processo convencional de nitretação em banho de sal, contendo cianeto e cianato. Também, estudou-se meios que reduzam os óxidos não aderentes, gerados durante o processo de nitretação. Os resultados indicam que os sais KNO3 e NaNO2 atuam na formação de uma camada nitrada, evidenciada pela mudança microestrutural e pelo aumento da dureza da camada, em relação ao material sem tratamento. Porém, dependendo das proporções entre sal atóxico e sal redutor de óxido, tem-se melhor acabamento superficial, o que contribui para o meio ambiente, pois evita a geração de resíduos na base de cianeto e cianato. Palavras-chave: Aço baixo carbono. Nitretação. Banho de sal atóxico. Abstract The objective of this article is to develop a method of nitriding in non-toxic salt baths, using potassium nitrate (KNO3) and sodium nitrite (NaNO2), as well as to evaluate the hardness and the visual aspect of the surface layer of a steel with 0.2% carbon, seeking for an alternative to reduce the environmental impact caused by the conventional process of nitriding in salt bath containing cyanide and cyanate. It was also studied some means that can reduce the non-adherent oxides generated during the nitriding process. The results indicate that the salts KNO3 and NaNO2 act in the formation of a nitrated layer, evidenced by a microstructural change and the increase of the layer hardness, in relation to the material without any treatment. However, depending on the proportions between non-toxic salt and oxide-reducing salt, there is a better surface finishing, which contributes to the environment, as it avoids the generation of cyanide and cyanate-based residues. Keywords: Low carbon steel. Nitriding. Non-toxic salt bath.

show abstract

“…Salt bath nitriding [3,4,5] is one of the most widely used thermo-chemical methods [6,7,8], which produces strong and shallow case with high compressive residual stresses on the surface of steel components such as gears, crankshafts, dies and tools [9,10,11]. Surface roughness of industrial components strongly affects their performance, i.e, many surface properties such as friction [12][13], surface wear [14], fluid flow in rough pipes [15] and the functioning of vacuum seals [16] are strictly dependent on surface roughness.…”

Section: Introductionmentioning

confidence: 99%

Effect of Salt Bath Nitriding on Surface Roughness Behaviour of Aisi 4140 Steel

Ghelloudj

Hannachi

Djebaili

2017

Acta Metall Slovaca

View full text Add to dashboard Cite

In the present research, AISI 4140 steel was nitrided in salt bath to study and analyze the behaviour of the surface roughness. The structural surface characterization behaviour of the nitrided steel was compared to the behaviour of the same steel which was untreated. The nitriding process was implemented in the salt bath component at ten different times (from 1 h to 10 h) when the temperature was constant at (580ºC). The influence of nitriding treatment on structural properties of the material was studied by scanning electron microscopy (SEM), microhardness tester and surface profilometer. It was found that salt bath nitriding was effective in improving the surface properties behaviour of this steel. Experimental results showed that the nitrides ε-Fe2-3(N,C) and γ'-Fe4(N,C) present in the compound layer increase the microhardness (406-502 HV0.3), the initial surface roughness values of nitrided samples were higher than those of unnitrided specimens, it also observed that the increasing the nitriding time increases the surface roughness parameters (Ra, Rq and Rz).Keywords: salt bath nitriding, AISI 4140 steel, microhardness, surface roughness IntroductionSurface topography is an important characteristic that determines, among other things, catalytic activity, electrochemical potential, adhesion, friction coefficient, susceptibility to wear and scuffing failure and aesthetic appearance [1][2]. Salt bath nitriding [3,4,5] is one of the most widely used thermo-chemical methods [6,7,8], which produces strong and shallow case with high compressive residual stresses on the surface of steel components such as gears, crankshafts, dies and tools [9,10,11]. Surface roughness of industrial components strongly affects their performance, i.e, many surface properties such as friction [12][13], surface wear [14], fluid flow in rough pipes [15] and the functioning of vacuum seals [16] are strictly dependent on surface roughness. In addition, surface roughness seems to be important in bioengineering for example in the joints of the bones [17]. Quite often small roughness is desired since small roughness reduces wear and energy loss, but when high friction is needed also the roughness should be larger. Hence, the inspection of surface roughness of the work piece is very important to assess the quality of a component. The quality of surface roughness is an important requirement for coated parts [18]. There are at least five different mechanisms by using the surface modification methods to increase the fretting resistance: (1) to induce a residual compressive stress; (2) to decrease the coefficient of friction; (3) to increase the surface hardness; (4) to alter the surface chemistry; (5) to increase the surface roughness [19].

show abstract

Effect of NaCl and CaCl2 additives on NaNO3 bath nitriding of steel

Cited by 14 publications

References 7 publications

A facile modification of g-C3N4 with enhanced photocatalytic activity for degradation of methylene blue

A facile modification of g-C3N4 with enhanced photocatalytic activity for degradation of methylene blue

Nitriding in low carbon steels using non-toxic salt baths

Effect of Salt Bath Nitriding on Surface Roughness Behaviour of Aisi 4140 Steel

Contact Info

Product

Resources

About