Effect of CO2 Laser Fluence on Cladding Geometrical Dimensions Alternations

2021 ◽  
Vol 39 (5A) ◽  
pp. 703-710
Author(s):  
Mohammed J. Kadhim ◽  
Mahdi M. Hanon ◽  
Suhair A. Hussein

Geometrical dimensions could play a potential role in the function of laser cladding of nickel-base powder on the cold-rolled carbon steel substrate. The geometrical dimensions and their impact on the efficiency of the process of laser cladding of nickel-base powder (Ni -10wt% Al) on cold rolled 0.2% carbon steel substrate was investigated. This work focused on the effect of laser-specific energy input of CO2laser. The geometrical dimensions of cladding regions are including cladding width, cladding height, depth of dilution, contact angle, dilution area, cladding area, and heat-affected zone dimensions determinations. The laser power (1.8 kW) was used at different traverse speeds (1.5, 3.6, 5, 7.1, 8.6, 12.5 mm/s) with (3mm) laser beam diameter. The feed rate was kept constant after many preliminary claddings at approximately 11 g/min. Fluence values ranged from (48-400J/mm2), and the power density value was (255W/mm2). A minimum dilution percentage (25%) was obtained at the highest fluence value (400 J/mm2). Observations were measured using an optical microscope, scanning electron microscopy, and Image software. Obtained results indicated that the increase in the fluence leads to an increase in height of cladding, HAZ region but lower depth of dilution

2021 ◽  
Vol 39 (7) ◽  
pp. 1052-1059
Author(s):  
Mohammed J. Kadhim ◽  
Mahdi M. Hanon ◽  
Suhair A. Hussain

In this article a 1.8kW continuous wave of high power CO2 laser was used to clad of a titular composition of Ni – 10 wt% Al powder on cold rolled 0.2% carbon steel substrate. The feed rate was kept constant after many preliminary claddings at approximately 11 g/min.  In order to produce clads with different specific energies and interaction times, different traverse speeds were used in the range of 1.5 to 12.5 mm/s. The microstructure of substrate was changed at the heat affected zones under the variety of specific energies. The cladded coatings showed the presence of ɣ solid solution and β (NiAlFe) phases. A strong metallurgical bonding produced between the substrate and the clad coat at fluence higher than 48 J/mm2. The changing in microstructure were observed using both microscope and SEM. The microhardness was evaluated using Vickerʼs microhardness test. The microstructure of the substrate was ferrite and pearlite transformed to martensite at the region adjacent to the clad interface. It followed by a three regions can be classified, a grain growth zone (large grains of austenite/ferrite and pearlite), recrystallization zone (fine grains of austenite/ferrite and pearlite) and recovery zone (the structure has a little changes from the structure of low carbon steel). The microhardness testing result showed higher values for the clad regions compared with substrate. This study emphasize the possibility to develop a temporary new graded material.


2016 ◽  
Vol 59 (1) ◽  
pp. 85-94 ◽  
Author(s):  
S. Zanzarin ◽  
S. Bengtsson ◽  
A. Molinari

2011 ◽  
Vol 696 ◽  
pp. 170-175 ◽  
Author(s):  
Komsan Ngamkham ◽  
Satian Niltawach ◽  
Somrerk Chandra-ambhorn

Hot-rolled low carbon steel strips were produced using two different finishing temperatures at 910 and 820 °C in an industrial hot-rolling line. Mechanical adhesion of scale on the steel substrate at 40 mm from the edge was investigated by tensile test. It was found that the strain initiating the first spallation of scale produced at higher finishing temperature was lower. Spallation ratio which is a spalled area of scale divided by the total area of scale examined under an optical microscope was steeper when the scale was produced at higher finishing temperature. The lower values of strain initiating the first spallation and the higher values of spallation ratio of scale formed both at higher finishing temperature were due to higher thickness of that scale. Pickling behaviour of the hot-rolled steels was investigated by immersing the studied steels in a 10%v/v HCl solution at 80 °C. X-ray diffraction (XRD) peak of hematite relative to that of iron decreased with pickling time and approached zero during pickling periods from 3 to 10 s, while magnetite-and-iron ratio gradually decreased and tended to be zero at longer pickling time. This might indicate the existence of hematite as the outermost layer of scale and subscale containing magnetite as the inner part.


2019 ◽  
Vol 24 (4) ◽  
pp. 51-58
Author(s):  
Le Hong Quan ◽  
Nguyen Van Chi ◽  
Mai Van Minh ◽  
Nong Quoc Quang ◽  
Dong Van Kien

The study examines the electrochemical properties of a coating based on water sodium silicate and pure zinc dust (ZSC, working title - TTL-VN) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl (SCE) reference electrode in 3 M solution of KCl, auxiliary electrode Pt (8x8 mm) and working electrodes (carbon steel with surface treatment up to Sa 2.5) for determination of corrosion potential (Ecorr) and calculation of equivalent electric circuits used for explanation of impedance measurement results. It was shown that electrochemical method is effective for study of corrosion characteristics of ZSC on steel. We proposed an interpretation of the deterioration over time of the ability of zinc particles in paint to provide cathodic protection for carbon steel. The results show that the value of Ecorr is between -0,9 and -1,1 V / SCE for ten days of diving. This means that there is an electrical contact between the zinc particles, which provides good cathodic protection for the steel substrate and most of the zinc particles were involved in the osmosis process. The good characteristics of the TTL-VN coating during immersion in a 3,5% NaCl solution can also be explained by the preservation of corrosive zinc products in the coating, which allows the creation of random barrier properties.


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