scholarly journals The Effect of Powder Composition on the Microstructure and Corrosion Resistance of Laser Cladding 60NiTi Alloy Coatings on SS 316L

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1104
Author(s):  
Zexu Du ◽  
Zhengfei Hu ◽  
Yuqiang Feng ◽  
Fan Mo

Two kinds of 60NiTi powders were prepared by pure Ni mixed with Ti powders, and 55NiTi alloy powder with pure Ni powder and both the powders were fully mixed by alcohol ball milling. Two kinds of coatings (denoted as 60Ni-40Ti and 55NiTi-5Ni) were prepared on a 316L stainless steel substrate by laser cladding. The microstructure, microhardness and electrochemical behavior of the prepared coatings were investigated extensively. The results show that 55NiTi-5Ni has a typical dendritic eutectic structure, but 60Ni-40Ti tends to form a eutectic network structure. The main phases in both coatings are (Ni, Fe)Ti and (Ni, Fe)3Ti; however, the (Ni, Fe)Ti phase is dominant in 55NiTi-5Ni, but the (Ni, Fe)3Ti phase is more prevalent in 60Ni-40Ti. The microhardness was significantly improved with the 316L stainless steel substrate, and the microhardness of 55NiTi-5Ni is slightly higher than 60Ni-40Ti. The corrosion resistance of the two coatings in 3.5 wt% NaCl solution also leads to significant improvements compared with the substrate, and the corrosion resistance of 55NiTi-5Ni was also increased. These different behaviors and characteristics might be related to the different microstructures. Uniform and fine eutectic structure in 55NiTi-5Ni coating lead to better performance, which is also conducive to the formation of the dense oxide film to improve corrosion resistance.

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 622
Author(s):  
Xiaolong Xie ◽  
Bingbing Yin ◽  
Fucheng Yin ◽  
Xuemei Ouyang

The corrosion of galvanizing equipment parts by liquid zinc is an urgent problem that needs solving. In this work, FeB-30 wt.% Al0.25FeNiCoCr cermet coating was deposited on the surface of 316L stainless steel by AC-HVAF to protect galvanizing equipment parts from corrosion by liquid zinc. The microstructures and phase compositions of powders and the coating were determined by SEM, EDS, and XRD in detail. Additionally, the microhardness, fracture toughness, abrasion wear resistance, and corrosion resistance of the coating to liquid zinc were also studied. The results indicate that the abrasion wear resistance and corrosion resistance of the coating are much better than that of the 316L stainless steel substrate. The failure of the coating in liquid zinc is mainly due to the penetration of liquid zinc into macro-cracks, which causes the coating to peel off.


2015 ◽  
Vol 1119 ◽  
pp. 628-632
Author(s):  
Alain Kusmoko ◽  
Druce Dunne ◽  
Hui Jun Li

Stellite 6 was deposited by laser cladding on a martensitic stainless steel substrate with energy inputs of 1 kW (MSS-1) and 1.8 kW (MSS-1.8). The chemical compositions and microstructures of these coatings were characterized by atomic absorption spectroscopy, optical microscopy and scanning electron microscopy. The microhardness of the coatings was measured and the wear mechanism of the coatings was assessed using a pin-on-plate (reciprocating) wear testing machine. The results showed less cracking and pore development for Stellite 6 coatings applied to the MSS steel substrate with the lower heat input (MSS-1). Further, the Stellite coating for MSS-1 was significantly harder than that obtained for MSS-1.8. The wear test results indicated that the weight loss for MSS-1 was much lower than for MSS-1.8. It is concluded that the lower hardness of the coating for MSS-1.8, markedly reduced the wear resistance of the Stellite 6 coating.


2010 ◽  
Vol 148-149 ◽  
pp. 740-743
Author(s):  
Wei Yan Liu ◽  
Xiu Yan Li ◽  
He Feng Wang ◽  
Rui Feng ◽  
Bin Tang

Titanium surface alloyed layer was fabricated on 316L stainless steel substrate at 1000°C by means of the plasma surface alloying technique. The content of element titanium in the surface alloyed layer shows gradually tapering from surface to the inside of the substrate and it means an excellent metallurgical binding between the surface modified layer and 316L stainless steel substrate. The hardness of the titanium surface alloyed Layer is 1305HK0.5, which is much larger than that of the 316L stainless steel substrate. The wear performance of the treated and untreated 316L stainless steel was studied using a ball-on-disc sliding wear machine. Although the titanium surface alloyed layer does not show a friction-reducing effect, it improves the wear resistance of 316L stainless steel significantly and its wear rate is only one-fifteenth of that for untreated 316L stainless steel.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 963
Author(s):  
Di Pei ◽  
Li Wang ◽  
Ming-hui Ding ◽  
Zhao-nan Hu ◽  
Jun-yu Zhao ◽  
...  

In the paper, by using radio frequency (RF) magnetron sputter technology, the HfC coating grew on a 316L stainless steel substrate in an Ar atmosphere at various substrate bias voltages from 0 to −200 V. From the X-ray diffraction (XRD) and transmission electron microscopy (TEM) experiments, the HfC coatings were well crystallized and (111) preferential growth had been successfully obtained by controlling bias voltage at −200 V. Nanoindentation experimental results for the prepared HfC coatings indicated that they possessed the maximum nanohardness due to the formation of the (111) orientation. The results of electrochemical measurements displayed that 316L stainless steel (316L) coated with the HfC coatings had better corrosion resistance than bare 316L. With the bias voltage increasing to −200 V, adhesion of the 316L substrate with the HfC coating could be greatly improved, as well as corrosion resistance. The antithrombogenicity of the HfC coatings was identified by platelet adhesive and hemolytic ratio assay in vitro. It was shown that the hemocompatibility of coated 316L had been improved greatly compared with bare 316L and the HfC coatings possessed better antithrombogenicity with the bias voltage elevating above −150 V.


Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 583 ◽  
Author(s):  
Pengxian Zhang ◽  
Yibin Pang ◽  
Mingwei Yu

WC-reinforced Ni60 composite coatings with different types of WC particles were prepared on 304 stainless steel surface by laser cladding. The influences of spherical WC, shaped WC, and flocculent WC on the microstructures and properties of composite coatings were investigated. The results showed that three types of WC particles distribute differently in the cladding coatings, with spherical WC particles stacking at the bottom, shaped WC aggregating at middle and lower parts, with flocculent WC particles dispersing homogeneously. The hardnesses, wear resistances, corrosion resistances, and thermal shock resistances of the coatings are significantly improved compared with the stainless steel substrate, regardless of the type of WC that is added, and especially with regard to the microhardness of the cladding coating; the addition of spherical or shaped WC particles can be up to 2000 HV0.05 in some areas. Flocculent WC, shaped WC, and spherical WC demonstrate large to small improvements in that order. From the results mentioned above, the addition of flocculent WC can produce a cladding coating with a uniform distribution of WC that is of higher quality compared with those from spherical WC and shaped WC.


2017 ◽  
Vol 48 (6) ◽  
pp. 2915-2926 ◽  
Author(s):  
Reena Awasthi ◽  
Geogy Abraham ◽  
Santosh Kumar ◽  
Kaustava Bhattacharyya ◽  
Nachiket Keskar ◽  
...  

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