HEAT TREATMENT OF THERMAL SPRAY COATINGS: A REVIEW

7/22/2019 HEAT TREATMENT OF THERMAL SPRAY COATINGS: A REVIEW

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INTERNATIONAL JOURNAL OFMATERIALS SCIENCE AND ENGINEERING

Volume 2, Nos. 1-2, January-December 2011, pp. 147-152

HEAT TREATMENT OF THERMAL SPRAY COATINGS: A REVIEW

Kovid Sharma*, Sukhpal Singh Chatha, Hazoor Singh & Harkulvinder Singh

Department of Mechanical Engineering,Yadavindra College of Engineering, Punjabi University,

Guru Kashi Campus, Talwandi Sabo, Bathinda, Punjab-151302, India

E-mails: [email protected], [email protected], [email protected]

Abstract: The Hot corrosion is the main and severe problem which can be controlled by thermal spray coatings. The various

Corrosion control measures include Surface Heat Treatment, Engineering Paints, Vitreous Enamelling, Cladding, Powder

coatings, Zinc coatings, Tin Plate, Electroplating, Cadmium Plating, Anodising (Anodizing), Thermal Spray Coatings., Plasma

Nitriding/Carburising/Boronising., Pack Cementation, Ion Implantation, Ceramic and Cermet materials., Chemical Vapour

Deposition, Physical Vapour Deposition. The demand for protective coatings has increased recently for almost all types of

super alloys with improved strength, since high-temperature corrosion problems become much more significant for these

alloys with increasing operating temperatures of modern heat engines. The Major areas where coatings have the application

are Power generation Industries, Ceramics Industries, Chemical Industries, Iron & steel Industries and Mining Industries etc.

Open or closed porosity in thermal spray coatings can originate from several different factors: partially or totally unmolten

particles, inadequate flow or fragmentation of the molten particle at impact, shadowing effects due to lower than the optimal

spray angle, and entrapped gas. The interconnected (open) porosity allows the corrosive media to reach the coating-substrateinterface, which eventually leads to delamination of the coatings. Although the development of the modern thermal spray

processes has decreased coating porosities, the transport of corrosive species to the substrate can still only be prevented by

coating post treatment. Therefore its of actual significance to develop an effective method to post treat the thermal spray

coatings to enhance their life in corrosive environment. In this paper author has reviewed the significance of heat treatment in

thermal spray coatings for improving their properties and has made an attempt to explore the potential of heat treatment

process in thermal spray coatings.

Keywords: Corrosion, Coatings, Thermal Spray, Heat Treatment.

International Science Press, ISSN: 0976-6243

* Corresponding Author: [email protected]

1. INTRODUCTION

Corrosion is a natural phenomenon. All natural processes

end toward the lowest possible energy states. As described

in the corrosion cycle of the steel shown in Fig. 1. The

iron and steel have a natural tendency to combine with

other chemical elements to return to their lowest energy

states & they frequently combine with oxygen and water,

both of which are present in most natural environments,

to form hydrated iron oxides (rust), similar in chemical

composition to the original iron ore (ASM International,

2000).

Corrosion is the deterioration of a material by its

reaction with the surroundings. It adversely affects those

properties that are to be preserved. At higher temperature,this mode of degradation is known as oxidation or dry

corrosion (Sidhu T. S. et al., 2006).

Metals and alloys sometimes experience accelerated

oxidation when their surfaces are covered with a thin

film of fused salt in an oxidizing atmosphere at elevated

temperatures. This mode of attack is called hot corrosion

(Sidhu T. S. et al., 2006; Sidhu, H.S. et al., 2006).

Sidhu Buta Singh and Prakash S. observe that

although corrosion problems cannot be completely

remedied, it is estimated that corrosion-related costs can

be reduced by more than 30% with development and useof better corrosion control technologies (Sidhu Buta

Singh and Prakash S., 2006).

Xue-mei OU.et al evaluates that main reason for hot

corrosion on the boiler tube surface is the impurities,

such as Na, K, and S, present in the coal being burned

(Xue-mei OU.et al., 2008).

The demand for protective coatings has increased

recently for almost all types of super alloys with improved

strength, since high-temperature corrosion problems

become much more significant for these alloys with

Figure 1: The Corrosion Cycle of Steel (ASM 2000)
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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148 International Journal of Materials Science and Engineering ( IJMSE)

increasing operating temperatures of modern heat engines

(Sidhu Buta Singh and Prakash S., 2005).

Hot corrosion has been observed in boilers, internal

combustion engines, gas turbines, fluidized bed

combustion and industrial waste incinerators since the

1940s. However, it became a topic of importance and

popular interest in the late 1960s when gas turbine enginesof military aircraft suffered severe corrosion attacks

during the Vietnam conflict while operating over and near

sea water. During operation, blades and vanes of gas

turbines are subjected to high thermal stresses and

mechanical loads. In addition, they are also attacked

chemically by oxidation and/or high-temperature

corrosion. Only composite materials are able to meet such

a demanding spectrum of requirements; the base material

provides the necessary mechanical properties and coatings

provide protection against oxidation and corrosion (Sidhu

et al., 2006).

2. THERMAL SPRAY COATINGS & PROCESSES

Methods for the deposition of protective coatings on heat-

resistance alloys (HRA) can be separated into two basic

groups : thermal diffusion, based on processes leading

to a change in the composition and structure of the

surface layer of the HRA as a result of its contact and

reaction with alloying chemical elements; and non-

diffusional, based on processes in which an external

(overlay) coating is deposited on the surface with little

inter-diffusion of elements only that necessary to

guarantee adherence (Podchernyaeva I. A. et al.,2000).

Sidhu T. S. et al. suggests that Nickel-based alloy

coatings show good high-temperature wear and corrosion

resistance. Wear resistance improves after adding W and

Mo elements to the alloy. Ni-based coatings are used in

applications when wear resistance combined with

oxidation or hot corrosion resistance is required. When

nickel is alloyed with chromium, this element oxidizes to

Cr2O

3at rates which could make it suitable for use up to

about 900C (Sidhu T. S. et al., 2006).

Abdi S. and Lebaili S. deposits NiCrBCSi metal (Fe)

to hard reset show better properties and performance

compared to hard chromium deposits. Including the filing

NiCrBCSi (Fe) type A, this may be an appropriate

alternative to hard chromium and enable better protection

of the environment. This is due to the existence of

microstructure, composed of the Ni3B nickel boride and

matrix reinforced by nano precipitates rich in chromium

(Abdi S. and Lebaili S. 2008).

Uusitalo M.A. deposits St35.8 steel, 13CrMo4-5 steel,

St35.8 steel with chromium and aluminium diffusion

coatings, and St35.8 steel with different kinds of thermal

sprayed coatings were used as test materials. In general,

spraying systems using high particle velocities produce

dense coatings with small splat size, high bonding strength

and large contact area between individual splats (M.A.

Uusitalo, 2002).

The most common coatings are WC-Co, WC-CoCr,

and Cr3C

2-NiCr systems. Cr

3C

2-NiCr coatings show

comparatively poorer tribological properties, but they aremuch more resistant at high temperatures and in

aggressive environments: for these reasons they are used,

for example, in steam turbine blades or in boiler tubes

for power generation (Kaur Manpreet et al., 2009).

On the other hand Aalamialeagha M. E.et al. reveals

that high Velocity Oxy-Fuel (HVOF) spray techniques

can produce high performance alloy and cermet coatings

for applications that require wear resistant surfaces.

HVOF coatings require the careful matching of the

powder feed material to the process variables e.g., fuel

type, fuel/oxygen ratio, together with the design andgeometry of the spray gun. (Aalamialeagha M. E.et al.,

2003).

Among the different thermal spray processes, Super

D-Gun and HVOF have different features, such as

geometry and powder feed respectively. For the Super

D-Gun process the gases (acetylene and oxygen) are

mixed along with a pulse of powder introduced into the

barrel. Detonation using a spark generates waves of high

temperature and pressure which heat the powder particles

to their melting point or above. (V.A.D. Souza, A. Neville,

2007).

So lot of techniques, such as Air plasma spray (APS),

Vacuum plasma spray (VPS), Solution-precursor plasma

spray (SPPS), Electron-beam physical vapor deposition

(EB-PVD), High velocity oxygen fuel spray (HVOF),

Magnetron sputtering, have been used to deposit MCrAlY

bond coat on super alloys (Zhiming Li, Z et al. 2010).

Porosity or voids in the coating micro structure is

an important issue in thermal spraying, as due to this

physical property, corrosion resistance of different

thermal spraying coatings differs. Dense coatings usually

provide better corrosion resistance than porous coatings

(Sidhu et al., 2006).

To reduce the interconnected porosity and inter splat

boundaries, coatings are post treated by various methods

such as heat treatment, sealing, laser remelting etc.

(Sundararajan et al., 2009, Ahmaniemi et al., 2002,

Serresa, 2011).

The Heat Treatment process is one of the post

treatment processes and widely used to reduce the

interconnected porosity and inter splat boundaries. Hence

to be reviewed and further helpful in the post treatments

of thermal spray coatings.


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Heat Treatment of Thermal Spray Coatings: A Review 149

3. HEATTREATMENT OFTHERMAL

SPRAY COATINGS

Heat treatment is a process of heating the metals or steel

alloys at high temperature for some fixed time which

changes the microstructure of the substrate. With

increasing heat treatment temperature, the density of

weakly/ unbounded inter-splat boundaries and porositydecrease with a corresponding increase in elastic modulus

(Sundararajan G. et al.2009).

When the alloys were thermally annealed, these

irregularities in the grain boundaries disappeared

(Gonzalez-Rodriguez J.G. et al., 2008). Generally, heat

treatment of thermally sprayed deposits can release

residual stress, decrease the porosity and improve the

microstructure and properties of the deposits (Wang H.T.,

2009).

4. SOME STUDIES ON HEATTREATMENT OF

THERMAL SPRAY COATINGS

As we found that Porosity or voids in the coating micro

structure is an important issue in thermal spraying, as

due to this physical property, corrosion resistance of

different thermal spraying coatings differs and to reduce

the interconnected porosity and inter splat boundaries,

coatings are post treated by various methods such as

heat treatment. Here are some studies on the heat

treatment of thermal spray coatings.

Gff L.et al reveals the results regarding the effect of

both carburizing flame and argon atmosphere post-heat

treatments on the microstructure and corrosion resistanceof NiCrWBSi coatings are reported. Both micro structural

characterization and porosity determination were carried

out before and after the heat treatments. It was determined

that both treatments had reduced the porosity considerably,

and this reduction was accompanied by pronounced micro

structural changes regarding the disappearance of the initial

lamellar structure, a more uniform distribution of the hard

phases, and a decrease in the number of micro cracks

and unmelted particles. Results from potentiodynamic

studies carried out in a 5% NaCl solution have indicated

an increase in the corrosion resistance of both heat-treated

coatings (Gff L.et al., 2011).

The hardness and wear resistance of a thermal-

sprayed self-fluxing alloy (Ni-17wt. % Cr-3. 3wt.%B-4.

3wt.%Si-4.2wt.%Fe-0.9wt.%C) is improved by adding

20 wt.% of B13

C2

to the powder and heating the coating

at 1030C in a vacuum of 102 Torr. Porosity is decreased

from 20 to 0.3 vol. % by the heating if pre-heating at

950C is carried out to facilitate the escape of trapped

gases. The presence of numerous precipitates of

Cr3C

2 and CrB in the coating is consistent with a Rockwell

hardness of HRC 63. The abrasive wear resistance is

much improved compared with that of Stellite 6 (Shieh

Yune-Hua et al., 1993).

Sundararajan G. et al. evaluates the response of cold

sprayed SS 316L coatings on mild steel substrate to

aqueous corrosion in a 0.1 N HNO3

solution as determined

using polarization tests. The corrosion behaviour of the

SS 316L coating was studied not only in the as-coatedcondition, but also after heat treatment at 400, 800 and

1100C. Heat treatment reduced the porosity, improved

inter-splat bonding, increased the elastic modulus and

more importantly increased the corrosion resistance of

the cold sprayed SS 316L coating (Sundararajan G. et al.

2009).

The in-situ co-deposition of Cr-Si into Cr17

Ni2

stainless steel (similar to AISI 431) was achieved using a

pack cementation process. Through the optimum

parameters, a coating containing approximately 27 wt.

% Cr and 2 wt.% Si was obtained, with a layer thickness

of approximately 120 mm. Studies showed that thethermal treatment of the coating resulted in a reduction

of tensile strength, but the improvement of impact

toughness, although the coating had little effect on the

mechanical properties of the bulk. Tempering at 300 or

450C improved the tensile strength and the impact

toughness of the steel at 9 and 55C, while tempering

at 550C reduced these mechanical properties. (Wei P.,

Wan X.R., 2000).

The corrosion performance of several NiAl alloys

in 62 mol% Li2CO

338 mol% K

2CO

3at 650 C has been

studied using the weight loss technique. Alloys included

50Ni50Al at. % (NiAl) and 75Ni25Al at. % (Ni3Al)

alloys with additions of 1, 3 and 5 at. % Li each one,

with or without a heat treatment at 400 C during 144 h.

For comparison, AISI-316L type stainless steel was also

studied. The tests were complemented by X-ray diffraction,

scanning electronic microscopy and micro-analyses.

Results showed that NiAl-base alloy without heat

treatment presented the lowest corrosion rate even lower

than Ni3Al alloy but still higher than conventional 316L-

type stainless steel. In general terms, by either by heat

treating these base alloys or by adding Li, the mass loss

was increased. This effect was produced because by

adding Li the adhesion of the external protective layer

was decreased by inducing a higher number of

discontinuities inside the grain boundaries. When the

alloys were thermally annealed, these irregularities in the

grain boundaries disappeared, decreasing the number of

paths for the outwards diffusion of Al from the alloy to

form the external, protective Al2O

3layer (Gonzalez-

Rodriguez J.G. et al., 2008).

It is difficult to deposit dense intermetallic compound

coatings by cold spraying directly using compound

feedstock powders due to their intrinsic low temperature


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brittleness. A method to prepare intermetallic compound

coatings in-situ employing cold spraying was developed

using a metastable alloy powder assisted with post heat

treatment. In this study, a nanostructured Fe (Al)/Al2O

3

composite alloy coating was prepared by cold spraying

of ball-milled powder. The cold-sprayed Fe (Al)/Al2O

3

composite alloy coating was evolved in-situ to FeAl/Al2O

3intermetallic composite coating through a post heat

treatment. The effect of heat treatment on the phase

formation, microstructure and micro hardness of cold-

sprayed Fe (Al)/Al2O

3composite coating was investigated.

The results showed that annealing at a temperature of

600C results in the complete transformation of the

Fe (Al) solid solution to a FeAl intermetallic compound.

Annealing temperature significantly influenced the

microstructure and micro hardness of the cold-sprayed

FeAl/Al2O

3coating. On raising the temperature to over

950 C, diffusion occurred not only in the coating but

also at the interface between the coating and substrate.

The micro hardness of the FeAl/Al2O

3coating was

maintained at about 600HV0.1

at an annealing temperature

below 500C, and gradually decreased to 400HV0.1

at

1100C (Wang Hong-Tao et al.2009).

A method to prepare intermetallic composite coatings

employing the cost-efficient electric arc spraying twin

wires assistant with suitable heat treatment was developed.

In this study, a FeAl composite coating was produced

by spraying twin wires, i.e. a carbon steel wire as the

anode and an aluminum wire as the cathode by Chen

Yongxiong et al. The inter-deposited FeAl coating was

transformed in-situ to FeAl intermetallic compositecoating after a post annealing treatment. The effect of

annealing treatment conditions on phase composition,

microstructure and mechanical properties of the coating

was investigated by using XRD, SEM, EDS and OM as

well as micro hardness tester. The results show that the

desirable intermetallic phases such as Fe2Al

5, FeAl and

Fe3Al are obtained under the annealing condition. The

main oxide in the coating is FeO which can partially

transform to Fe3O

4up to the annealing condition (Chen

Yongxiong et al., 2009).

G. Bolelli et al. evaluated the effect of a 600C, 1 h

heat treatment on the corrosion performance of threeHVOF-sprayed metal alloy coatings by electrochemical

corrosion tests and corrodkote test. In general, the heat

treatment has two major effects on the tested coatings: it

improves interlamellar cohesion, reducing active corrosion

along interlamellar boundaries, but can also trigger

galvanic microcells at intralamellar level, because of the

formation of secondary phases. The first, beneficial

effect prevails in the case of Co800 and D4006 coatings,

so that an overall improvement in their corrosion

resistance is found and they have lower corrosion current

density, less active corrosion at interlamellar boundaries

and improved corrodkote test resistance. The heat

treatment is therefore an effective way to improve the

overall performance of the Co800 and D4006 coatings.

The properties of the heat-treated Co800 coating are

particularly significant when compared to those of

electrolytic hard chrome (EHC). By coupling the corrosion

test outcomes to former results on tribological behaviour,

we find that the corrosion resistance of heat-treated

Co800 is comparable to that of EHC and its tribological

characteristics far surpass EHC under various contact

conditions. By contrast, the effects of the heat treatment

on the corrosion resistance of Ni700 are less obvious.

Most importantly, after the heat treatment, the Ni700

coating shows greater sensitivity to crevice corrosion,

so that its overall corrosion resistance may seem to be

reduced by the heat treatment (G. Bolelli et al. 2008).

G. Bolelli and L. Lusvarghi examined the tribological

behavior of HVOF sprayed Co-28%Mo-17%Cr-3%Si

coatings, both as deposited and after heat treatments,correlating it with microstructural and micromechanical

features. A significant degree of splat boundary oxidation

exists in the as-sprayed coating, because of exothermic

oxidative reaction occurring at T > 810C. This coating

is mainly amorphous due to splat quenching; thus, it has

low hardness and toughness, resulting in poor tribological

performanceparticularly, its low hardness promotes

adhesive wear against 100Cr6

steel pins. Adhesion causes

a rapid increase in friction coefficient, and consequently

the contact point temperature reaches a critical value

where rapid oxidation occurs. Oxides decrease the friction

coefficient, but they are not particularly adherent to thecontacting surfaces and mostly form debris. Therefore,

friction increases again and continues to oscillate

periodically because adhesive wear continues to raise flash

temperature up to the critical value. Most of the wear

loss occurs in the first stage, where adhesion is particularly

severe due to direct contact between metallic surfaces.

In the tests against alumina pin, the sample wear rate is

smaller because less adhesion takes place; abrasive wear

is prevalent, but the Co-base alloy has sufficient intrinsic

plasticity to withstand it without undergoing too much

cutting wear. However, the fast oxidation process, with

peculiar friction coefficient behavior, still takes place.While the 200 and 400C heat treatments do not cause

any major change (the former one even degrading the

coating properties), the 600C treatment causes the

appearance of sub-micrometric crystalline regions

improving hardness and elastic modulus. Adhesive

phenomena between coating and steel pin are thus

definitely reduced; the wear loss is negligible for the

coating and decreased by two orders of magnitude for

the pin; no friction coefficient peaks occur nor is fast

oxidation started. Instead, friction coefficient soon gets

to a steady value. The coating wear rate against alumina


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Heat Treatment of Thermal Spray Coatings: A Review 151

pin is not significantly changed because abrasive wear

still prevails, so there are no major changes in the wear

process. However, adhesive phenomena are further

reduced, preventing the appearance of friction coefficient

peaks and of fast oxidation. Thus, performing a 600C,

1 h heat treatment in air could be suggested as a way to

improve the sliding wear performance of the present alloyat room temperature. The 600C heat treated coating wear

rates are lower than those recorded by the authors for

hard chrome platings at room temperature under the same

testing conditions (G. Bolelli and L. Lusvarghi, 2006).

Hence it has been observed that with the heat

treatment of thermal spray coatings better results can be

obtained in post treatment of the coatings for enhancing

their life for different applications but not much work

has been done in this field to post treat the coatings and

by changing the parameters like Temperature and time

of heat treatment better results can be obtained in post

treatment of the coatings. Fig. 2 describes the some ofthe work done in the heat treatment in the shape of

pyramid.

5. CONCLUSION

Thermal Spray Coatings are very effective for

corrosion, erosion and wear applications, but due to

interconnected porosity the corrosive species are able

to penetrate and attack the substrate via

interconnected network of voids and oxide at splat

boundaries, hence their life is reduced.

Further the various Post treatments of thermal spraycoatings are effective methods to improve their life.

Heat treatment is one of them which found to give

better results in reducing the porosity considerably

and improves interlamellar cohesion.

From the literature it has been observed that not much

work has been done in this field to post treat the

coatings and by changing the parameters like

Temperature and time of heat treatment better results

can be obtained in post treatment of the coatings for

enhancing their life for different applications.

References

[1] ASM International, 2000, Corrosion: Understanding the

Basics, ASM Int ernational, Materials Park, Ohio, USA,

(#06691G).

[2] Buta Singh Sidhu, S. Prakash, Studies on the Behaviour of Stellite-

6 as Plasma Sprayed and Laser Remelted Coatings in Molten Salt

Environment at 900 C Under Cyclic Conditions, Journal of

Materials Processing Technology , 172, (2006), pp. 52-63.

[3] Buta Singh Sidhu and S. Prakash, Nickel-Chromium Plasma

Spray Coatings: A Way to Enhance Degradation Resistance of

Boiler Tube Steels in Boiler Environment, JTTEE5, 15:131-

140 (Submitted February 17, 2005; in Revised form July 14,

2005).Figure 2: Pyramid Showing the Summery of the Work Done

in the Field of Heat Treatment as Post Treatment


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[4] G. Bolelli and L. Lusvarghi, Heat Treatment Effects on the

Tribological Performance of HVOF Sprayed Co-Mo-Cr-Si

Coatings, JTTEE5, 15, (2006), pp. 802-810.

[5] G. Bolelli et al., Heat Treatment Effects on the Corrosion

Resistance of Some HVOF-sprayed Metal Alloy Coatings,

Surface & Coatings Technology, 202, (2008), pp. 4839-4847.

[6] G. Sundararajan, P. Sudharshan Phani, A. Jyothirmayi & Ravi

C. Gundakaram, The Influence of Heat Treatment on theMicro Structural, Mechanical and Corrosion Behaviour of Cold

Sprayed SS 316L Coatings,J. of Mater Sci., (2009), 44:2320-

2326.

[7] Hong-Tao Wang, Chang-Jiu Li, Guan-Jun Yang, Cheng-Xing

Li, Effect of Heat Treatment on the Microstructure and

Property of Cold-sprayed Nano Structured FeAl/Al2O

3

Intermetallic Composite Coating, Vacuum, 83, (2009), pp.

146-152.

[8] I. A. Podchernyaeva, A. D. Panasyuk, M. A. Teplenko, and

V. I. Podolskii, Protective Coatings on Heat-Resistant Nickel

Alloys (Review), Powder Metallurgy and Metal Ceramics,

39, Nos. 9-10, 2000.

[9] J.G. Gonzalez-Rodriguez, E. Mejia, I. Rosales, V. M. Salinas-

Bravo, G. Rosas, A. MArtinez-Villafane, Effect of HeatTreatment and Chemical Composition on the Corrosion

Behavior of NiAl Intermetallics in Molten (Li + K) Carbonate,

Journal of Power Sources, 176, (2008), pp. 215-221.

[10] L. Gff, M.A. Pareto and M.H. Staia, Effect of Post-heat

Treatment on the Corrosion Resistance of NiWCrBSi HVOF

Coatings in Chloride Solution,JTTEE5, 11:95-99.

[11] M. E. Aalamialeagha, S. J. Harris, M. Emamighomi, Influence

of the HVOF Spraying Process on the Microstructure and

Corrosion Behaviour of Ni-20%Cr Coatings, Journal of

Materials Science, 38, (2003), pp. 4587-4596.

[12] M.A. Uusitalo, P.M.J. Vuoristo, T.A. Mantyla, Elevated

Temperature Erosioncorrosion of Thermal Sprayed Coatings

in Chlorine Containing Environments, Wear, 252, (2002),

pp. 586-594.

[13] Manpreet Kaur, Harpreet Singh, and Satya Prakash, High-

Temperature Corrosion Studies of HVOF-Sprayed Cr3C

2-NiCr

Coating on SAE-347H Boiler Steel, JTTEE5 , 18:619-632

(Submitted January 28, 2009; in Revised form July 3, 2009).

[14] N. Serresa, Franc., O. Hlawka, S. Costil, C. Langlade, F. Machi.

Corrosion Properties of in Situ Laser Remelted NiCrBSi

Coatings Comparison with Hard Chromium Coatings, J. of

Mater. Process. Technol., 211 (2011), pp. 133-140.

[15] OU Xue-mei, SUN Zhi, SUN Min, ZOU Duan-lian, Hot-

corrosion Mechanism of Ni-Cr Coatings at 650C under

Different Simulated Corrosion Conditions, J. China Univ

Mining & Technol , 18, (2008), pp. 0444-0448.

[16] P. Wei, X.R. Wan, The Effect of a Coating Heat-treatment

on Cr-Si and Heat-treatment on the Mechanical Properties of

Cr17

Ni2Stainless Steel Surface and Coatings Technology, 132,

(2000), pp. 137-142.

[17] Pawlowski L., 2008, The Science and Engineering of Thermal

Spray Coatings Second Edition, John Wiley & Sons Ltd, The

Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ,

England., pp. 67-113.

[18] S. Abdi and S. Lebaili, Alternative to Chromium, a Hard Alloy

Powder NiCrBCSi (Fe) Coatings Thermally Sprayed on 60CrMn4

Steel, Phase and Comportments, Proceedings of the JMSM

2008 Conference.

[19] S. Ahmaniemi, P. Vuoristo, T. Mantyla, Improved Sealing

Treatments for Thick Thermal Barrier Coatings, Surf. and

Coat. Technol., 151-152, (2002), pp. 412-417.

[20] Souza V.A.D. Neville A., Aspects of Microstructure on the

Synergy and Overall Material Loss of Thermal Spray Coatings

in Erosioncorrosion Environments, Wear, 263 , (2007),pp. 339-346.

[21] T. S. Sidhu, S. Prakash and R. D. Agrawal, Hot Corrosion and

Performance of Nickel-based Coatings, Current Science, 90,

No. 1, 10 January 2006.

[22] T.S. Sidhu, S. Prakash, and R.D. Agrawal, Characterizations

and Hot Corrosion Resistance of Cr3C

2-NiCr Coating on

Ni-Base Super Alloys in an Aggressive Environment,JTTEE5,

15:811-816 (Submitted April 2, 2006; in Revised form July 2,

2006).

[23] Yongxiong Chen, Xiubing Liang, Shicheng Wei, Yan Liu, Binshi,

Xu Heat Treatment Induced Intermetallic Phase Transition

of Arc-sprayed Coating Prepared by the Wires Combination of

Aluminum-cathode and Steel-anode Applied Surface Science,

255, (2009), pp. 8299-8304.

[24] Yune-Hua Shieh and Jia-tzann Wang, Han C. Shih and Shinn-

Tyan Wu, Alloying and Post-heat Treatment of Thermal-

sprayed Coatings of Self-fluxing Alloys Surface and Coatings

Technology, 58, Issue 1,18 June 1993, Pages 73-77.

[25] Zhiming Li, Shiqiang Qian, Wei Wang., Characterization and

Oxidation Behavior of NiCoCrAlY Coating Fabricated by

Electro-phoretic Deposition and Vacuum Heat Treatment.

Applied Surface Science, xxx, (2010), pp. xxxxxx.


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