scholarly journals Ultrasonic Surface Hardening of Low Carbon Steels and Non-Ferrous Alloys

2019 ◽  
Vol 297 ◽  
pp. 05005
Author(s):  
Kharis Rakhimyanov ◽  
Viktor Gileta ◽  
Artem Samul
Keyword(s):  
Surface Layer ◽  
Surface Hardening ◽  
Low Carbon Steel ◽  
Relative Displacement ◽  
Carbon Steels ◽  
Low Carbon ◽  
Ferrous Alloys ◽  
Low Carbon Steels ◽  
Geometrical State

The possibility of using ultrasonic surface hardening with implementing the indenter tangential oscillations to the deformed surface to improve the quality of the detail surface layer produced from low carbon steel and ferrous alloys is considered in the paper. The mathematical description of the trajectory of the relative displacement of the instrument and the detail is presented. It is established that the important technological parameter influencing the character of the formed micro-geometry is the angle between the instrument vectors and the detail speed. The effect of the technological factors of the ultrasonic surface hardening on the amplitude and spacing parameters of the surface roughness are revealed. The results of the research showed that the ultrasonic processing at the tangential oscillations of the indenter allows forming a stable micro-geometrical state of the surface layer with low values of the amplitude and spacing parameters on the details made from non-ferrous alloys and low carbon steels.

scholarly journals Nitriding in low carbon steels using non-toxic salt baths

2019 ◽  
pp. 177-186
Author(s):  
Vinicius Timm Bonow ◽  
Débora Stefani Maciel ◽  
André Zimmer ◽  
Cinthia Gabriely Zimmer
Keyword(s):  
Surface Layer ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Salt Bath ◽  
Potassium Nitrate ◽  
Carbon Steels ◽  
Microstructural Change ◽  
Surface Finishing ◽  
Low Carbon ◽  
Low Carbon Steels

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.

Effect of Soaking Time on Paste Carburizing of Carburized Low Carbon Steel

2017 ◽  
Vol 740 ◽  
pp. 93-99
Author(s):  
Muhammad Hafizuddin Jumadin ◽  
Bulan Abdullah ◽  
Muhammad Hussain Ismail ◽  
Siti Khadijah Alias ◽  
Samsiah Ahmad
Keyword(s):  
Carbon Steel ◽  
Carbon Content ◽  
Low Carbon Steel ◽  
Case Depth ◽  
Carbon Steels ◽  
Low Carbon ◽  
Soaking Time ◽  
Low Carbon Steels ◽  
Carburized Steel ◽  
Carburizing Process

Increase of soaking time contributed to the effectiveness of case depth formation, hardness properties and carbon content of carburized steel. This paper investigates the effect of different soaking time (7-9 hours) using powder and paste compound to the carburized steel. Low carbon steels were carburized using powder and paste compound for 7, 8 and 9 hours at temperature 1000°C. The transformation of microstructure and formation carbon rich layer was observed under microscope. The microhardness profiles were analyzed to investigate the length of case depth produced after the carburizing process. The increment of carbon content was considered to find the correlation between types of carburizing compound with time. Results shows that the longer carburized steel was soaked, the higher potential in formation of carbon rich layer, case depth and carbon content, which led to better hardness properties for carburized low carbon steel. Longer soaking time, 9 hours has a higher dispersion of carbon up to 41%-51% compare to 8 hours and 7 hours. By using paste carburizing, it has more potential of carbon atom to merge the microstructure to transform into cementite (1.53 wt% C) compare to powder (0.97 wt% C), which increases the hardness of carburized steel (13% higher).

Predicting the Effects of Cold Working on the Machining Characteristics of Low Carbon Steels

1987 ◽  
Vol 109 (3) ◽  
pp. 257-264 ◽  
Author(s):  
E. M. Kopalinsky ◽  
P. L. B. Oxley
Keyword(s):  
Flow Stress ◽  
Carbon Steel ◽  
Cutting Forces ◽  
Cold Working ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Steel Work ◽  
Machining Characteristics

Experiments show that the cold working of low carbon steel work materials can improve their machinability by reducing cutting forces and improving surface finish and tool life. The somewhat paradoxical result of reducing cutting forces by cold working a material so that its hardness is increased is explained in this paper by using a machining theory which takes account of the flow stress properties of the work material and can thus allow for the effects of cold working.

High Temperature Corrosion of Al Hot-Dipped Low Carbon Steels in N2/H2S-Mixed Gases

2016 ◽  
Vol 369 ◽  
pp. 59-64
Author(s):  
Muhammad Ali Abro ◽  
Dong Bok Lee
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Alloy Layer ◽  
High Temperature Corrosion ◽  
Carbon Steels ◽  
Low Carbon ◽  
Mixed Gas ◽  
Low Carbon Steels ◽  
Mixed Gases

A low carbon steel was hot-dip aluminized, and corroded in the N2/0.4%H2S-mixed gas at 650-850°C for 20-50 h in order to find the effect of aluminizing on the high-temperature corrosion of the low carbon steel in the H2S environment. A thin Al topcoat and a thick Al-Fe alloy layer that consisted primarily of Al5Fe2 and some FeAl and Al3Fe formed on the surface after aluminizing. The corrosion rate increased with an increase in temperature. Hot-dip aluminizing increased the corrosion resistance of the carbon steel through forming a thin protective α-Al2O3 scale on the surface. The α-Al2O3 scale was susceptible to spallation. During corrosion, internal voids formed in the Al-Fe alloy layer, where the Al5Fe2, AlFe, and Al3Fe compounds gradually transformed through interdiffusion.

The Investigation on Wire Rod Materials of Low Carbon Steels and Extra Low Carbon Steels

2013 ◽  
Vol 690-693 ◽  
pp. 262-269
Author(s):  
Ho Hua Chung ◽  
Tsong Hsin Chen
Keyword(s):  
Low Carbon Steel ◽  
Carbon Steels ◽  
Titanium Nitrides ◽  
Low Carbon ◽  
Cold Forming ◽  
Low Carbon Steels ◽  
Wire Rod ◽  
The Wire ◽  
Micro Structures ◽  
Precipitation Phase

In this study, three kinds of rolled wire rod materials constantly used on screws and bolts are concerned. The relation among mechanical properties, phase ratios, micro-structures and grain sizes is investigated on the wire materials of low carbon steels and extra low carbon steels. Also the Electron Microscope and Energy Spectrum analysis are applied to distinguish the type of Precipitation phase. The results are shown that the precipitation phase of titanium nitrides and titanium carbides exist in the extra low carbon steel so that the hardness ratio of the wire materials with extra low carbons after cold forming is higher than that of the wire materials with low carbons for around 10%. In addition, The wire rod materials with course ferrite grains mainly added by titanium elements in extra low carbon steels could be made as the wire materials for cold processing and it still kept good ductility not necessary to be softened under heat treatment. So in the research of function comparisons, to save cost expenses through cold forming without annealing process is expected.

Increasing in expediency of cold forging of parts made of iron powders in comparison with parts made of low-carbon steels

2020 ◽  
pp. 494-501
Author(s):  
A.M. Dmitriev ◽  
N.V. Korobova
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Cold Forging ◽  
Cold Extrusion ◽  
Contact Friction ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Strength Limit ◽  
Iron Based

The quality of parts such as deep cylindrical cups made by cold forging from low-carbon steel and sintered billets from iron powder is compared. Technological processes from production of iron-based powder parts and press equipment used in mechanical engineering and in powder metallurgy are described. Cold forging of powder billets and billets from low-carbon steels is carried out on press specialized for extrusion with the creation of actively directed contact friction stresses between the deformable billet and the die. It is shown that cold extrusion of cup-type parts with actively directed contact friction stresses makes it possible to manufacture parts from iron-based powder with density equal to 98...99 % of the theoretical iron density. However parts from low-carbon steel have strength limit greater than that of powder parts. Powder cups do not have the anisotropy of properties typical for cups from low-carbon steels.

Determination of the Recovery Kinetics during the Annealing of Cold Rolled Low Carbon Steels

2004 ◽  
Vol 467-470 ◽  
pp. 141-146 ◽  
Author(s):  
Ane Martínez-de-Guereñu ◽  
F. Arizti ◽  
Isabel Gutiérrez
Keyword(s):  
Coercive Field ◽  
Low Temperatures ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Dislocation Hardening ◽  
Cold Rolled ◽  
Kinetics Of

A cold rolled low carbon steel has been annealed at sufficiently low temperatures (300 to 500 °C) in order to promote recovery without interaction with recrystallization. The recovery kinetics has been followed by using magnetic coercive field (Hc) measurements. The microstructural changes associated with the observed decrease in Hc, produced by the recovery, have been analysed by TEM observations. The experimental data have been adequately modelled using various formulations reported in the literature. The kinetics of the dislocation hardening contribution to the yield stress has been derived from the kinetics of the coercive field, taking into account the existing linear relationship between both variables.

Surface Microstructure and Texture Evolution during Interrupted Annealing in Ultra Low Carbon Steels

2010 ◽  
Vol 89-91 ◽  
pp. 202-207
Author(s):  
J. Gautam ◽  
Roumen H. Petrov ◽  
Leo Kestens ◽  
Elke Leunis
Keyword(s):  
Phase Transformation ◽  
Surface Texture ◽  
Texture Evolution ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Control Surface ◽  
Surface Microstructure ◽  
Low Carbon ◽  
Metal Vapour ◽  
Low Carbon Steels

The austenite-to-ferrite phase transformation, which is an inherent feature of low-alloyed ultra low carbon steels, has scarcely been investigated to control surface texture and microstructure evolution. This paper investigates the systematic evolution of texture and microstructure at the metal-vapour interface during interrupted annealing in vacuum. Interrupted annealing experiments were carried out on three ultra low carbon steel sheets alloyed with Mn, Al and Si. The texture and microstructures have been investigated by X-ray diffraction and SEM-EBSD techniques. These results reveal a very clear variation in the surface texture components as well as in the surface microstructure after BCC recrystallisation and double  transformation interrupted annealing. The recrystallisation texture consists mainly of a <111>//ND fibre, while the transformation texture at the surface exhibits a <100>// ND fibre in combination with components of the <110> //ND fibre. It has been revealed that the latter specific surface texture was present in a monolayer of outer surface grains which were in direct contact with the vapour atmosphere. This observed phenomenon could be explained by considering the role of surface energy anisotropy occurring during phase transformation annealing.

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