Assessment of Cavitation Erosion of Gas-Nitrided Cr-Ni-Mo Steels

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Ion Mitelea ◽  
Cristian Ghera ◽  
Ilare Bordeaşu ◽  
Corneliu Crăciunescu
Keyword(s):  
Electron Microscopy ◽  
Erosion Rate ◽  
Structural Changes ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Thermochemical Treatment ◽  
Gas Nitriding ◽  
The Mean ◽  
Cavitation Erosion Resistance ◽  
Scanning Electron

The effect of the gas-nitriding thermochemical treatment on the cavitation erosion resistance of a Cr-Ni-Mo alloy is analyzed using a piezoceramic vibrating equipment and following the ASTM G32-2010 standard. The evaluation of the cavitation erosion behavior was made based on the analysis of the mean depth of erosion (MDE) and mean depth of erosion rate (MDER), for samples subjected to the cavitation erosion for different times. The surface topography and the structural changes in the marginal layer were analyzed through optical and scanning electron microscopy. Following nitriding the cavitation erosion resistance was about 9.6 times higher compared to the annealed state and about 8.2 times higher compared to the hardened and tempered state.

Influence of microwave heating on metallurgical and mechanical properties of Ni-40Cr3C2 composite clads in the context of cavitation erosion resistance characteristics

2020 ◽  
pp. 095440622094034
Author(s):  
Jonty Mago ◽  
Sandeep Bansal ◽  
Dheeraj Gupta ◽  
Vivek Jain
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Microwave Heating ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Material System ◽  
Cavitation Erosion Resistance ◽  
Scanning Electron

Surface modification is one of the most reliable solutions for protecting the material damage in hydraulic turbines due to cavitation phenomena. However, the conventional coating/cladding process has many drawbacks like high porosity, weak adhesion strength, and poor fracture toughness. In contrast, the cladding process with microwave hybrid heating can overcome these limitations. Hence, this study aims to develop the microwave processed composite clad of Ni-based alloy with 40% Cr3C2 (by wt.) on SS-316 substrate in the domestic microwave oven of 2.45 GHz frequency and 900 W power. The selection of the material system for this study was based on mitigating the effect of cavitation erosion. The thorough metallurgical and mechanical characterization of the developed composite clad was done. Microstructural characterization using scanning electron microscopy revealed that the developed composite clads had a uniform thickness of 600 µm and free from interfacial cracks and visible pores (measured porosity ∼1.67% – as per ASTM B276). Uniformly dispersed hexagonal and stripe type carbides precipitate in the Ni-based alloy matrix of the composite clad was observed through scanning electron microscopy images. X-ray diffraction analysis shows that various hard carbides (SiC, Ni3C, Cr3Ni2SiC, Cr7C3, and NiC) and intermetallic (Ni3Fe, Ni2Si, and Cr3Si) phases were formed during microwave heating. The microhardness, flexural strength, fracture toughness of the Ni-40Cr3C2 clads were evaluated. The results reveal that the composite clad possesses microhardness = 605 ± 80 HV0.3 (∼3 times SS-316), flexural strength = 813.23 ± 16.2 MPa, and fracture toughness = 7.44 ± 0.2 MPa√m. The appropriate value of these properties makes this composite clad suitable for cavitation erosion resistance application.

Cavitation Erosion Resistance of Sputter-Deposited Cr3Si Film on Stainless Steel

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Shuyun Jiang ◽  
Hongqin Ding ◽  
Jiang Xu
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Surface Damage ◽  
304 Stainless Steel ◽  
Glow Discharge Plasma ◽  
Damage Degree ◽  
Average Grain Size ◽  
Cavitation Erosion Resistance

In this technical brief, a Cr3Si nanocrystalline film was deposited on 304 stainless steel (SS) substrate using a double glow discharge plasma technique. The film was characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy, nanohardness tester, and scratch tester. The as-deposited film with a thickness of 5 μm consisted of A15 structured Cr3Si phase with an average grain size of 8 nm. The hardness values of the film were determined to be 26 GPa, which was ten times greater than 304 SS. A self-designed ultrasonic vibration cavitation erosion apparatus was employed to evaluate the cavitation erosion resistance of the Cr3Si film. The results showed that after cavitation tests of 30 hrs, the erosion mass loss of the film was only 60% of that for 304 SS substrate. SEM observation of the erosion surfaces indicated that the surface damage degree of the Cr3Si film is significantly less than that of 304 SS.

Influence of Spatial Structures of 316L Stainless Steel on its Cavitation Erosion Resistance

2014 ◽  
Vol 225 ◽  
pp. 109-114
Author(s):  
Beata Śniegocka ◽  
Marek Szkodo ◽  
Jarosław Chmiel
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cavitation Erosion ◽  
316L Stainless Steel ◽  
Erosion Resistance ◽  
Spatial Structures ◽  
Erosion Test ◽  
Cavitation Erosion Resistance ◽  
Scanning Electron

Cavitation erosion performance of modified macroscopic internal structure 316L stainless steel was investigated. The samples processed by means of SLM method were subjected to cavitation erosion test. The scanning electron microscope Philips 30/ESEM was used to examine morphology of eroded surface.

scholarly journals Microstructure and Cavitation Erosion Resistance of HVOF Deposited WC-Co Coatings with Different Sized WC

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 307 ◽  
Author(s):  
Xiang Ding ◽  
Du Ke ◽  
Chengqing Yuan ◽  
Zhangxiong Ding ◽  
Xudong Cheng
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
The Other ◽  
Fuel Spray ◽  
X Ray ◽  
Cavitation Erosion Resistance ◽  
Scanning Electron ◽  
Conventional Coating

Conventional, multimodal and nanostructured WC-12Co coatings with different WC sizes and distributions were prepared by high velocity oxy-fuel spray (HVOF). The micrographs and structures of the coatings were analyzed by scanning electron microscope (SEM), X-ray diffractometer (XRD) et al. The porosity, microhardness and fracture toughness of the WC-Co coatings were measured. The coating resistance to cavitation erosion (CE) was investigated by ultrasonic vibration cavitation equipment and the cavitation mechanisms were explored. Results show that there is serious WC decarburization in nanostructured and multimodal WC-Co coatings with the formation of W2C and W phases. The nanostructured WC-Co coating has the densest microstructure with lowest porosity compared to the other two WC-Co coatings, as well as the highest fracture toughness among the three coatings. It was also discovered that the nanostructured WC-Co coating exhibits the best CE resistance and that the CE rate is approximately one-third in comparison with conventional coating.

Study on Cavitation Erosion Properties of Stainless Steel Vane Wheel Enhanced by Electro-Spark Deposition (ESD) Technology

2011 ◽  
Vol 239-242 ◽  
pp. 2229-2232 ◽  
Author(s):  
Chang Jun Chen ◽  
Yan Zhan Su ◽  
Qin Cao ◽  
Min Zhang
Keyword(s):  
Stainless Steel ◽  
Cavitation Erosion ◽  
Energy Dispersive Spectrometry ◽  
Erosion Resistance ◽  
Optical Microscope ◽  
Ultrasonic Equipment ◽  
Erosion Properties ◽  
Preliminary Study ◽  
Cavitation Erosion Resistance ◽  
Scanning Electron

In this paper, Electro-Spark Deposition (ESD) technology was used to enhance the cavitation erosion resistance of the stainless steel. The microstructure and composition of the deposition layers were studied by optical microscope (OM), scanning electron microscope (SEM) and energy dispersive Spectrometry (EDS) on cavitation erosion resistance was investigated. The microhardness was measured too. The cavitation erosion resistance was measured in ultrasonic equipment. The preliminary study confirmed that the cavitation erosion resistance of the deposition layer was enhanced compared to the untreated substrate. Now, vane wheel made of cast-iron, stainless steel and oil bump damaged by cavitation erosion have been repaired by ESD. And the properties of the repaired vane wheels were the same as the new ones.

Surface modification by gas nitriding for improving cavitation erosion resistance of CP-Ti

2014 ◽  
Vol 298 ◽  
pp. 164-170 ◽  
Author(s):  
Haibin Li ◽  
Zhenduo Cui ◽  
Zhaoyang Li ◽  
Shengli Zhu ◽  
Xianjin Yang
Keyword(s):  
Surface Modification ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Gas Nitriding ◽  
Cavitation Erosion Resistance ◽  
Cp Ti

Cavitation erosion resistance of ZrC nanoceramic coating

2019 ◽  
Vol 234 (6) ◽  
pp. 833-841 ◽  
Author(s):  
Hongqin Ding ◽  
Shuyun Jiang ◽  
Jiang Xu
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Volume Loss ◽  
Electrochemical Test ◽  
316 Stainless Steel ◽  
Cavitation Erosion Resistance ◽  
Scanning Electron

A ZrC nanoceramic coating was prepared on the bare 316 stainless steel for improving the cavitation erosion resistance by the double glow discharge sputter technique. The phase constitution and surface microstructure of the ZrC nanoceramic coating were characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscopy. A 10-µm-thick ZrC nanoceramic coating exhibited equiaxed grains with an average grain size of 9 nm. The adhesion strength and mechanical properties for the ZrC nanoceramic coating were evaluated by scratch test and nanoindentation. The hardness value of the ZrC nanoceramic coating was about four times that of the uncoated 316 stainless steel. The cavitation erosion behavior of the ZrC nanoceramic coating in tap water was characterized by the combination of an ultrasonic vibration system with an electrochemical workstation. The volume loss, erosion depth, scanning electron microscope morphology, and electrochemical test were adopted to assess the surface damage of the ZrC nanoceramic coating. The results show that the volume loss of the ZrC nanoceramic coating is 0.53 mm3, which is only 46% of the 316 stainless steel (1.14 mm3) after cavitation test, and erosion damage of the ZrC nanoceramic coating is significantly decreased as compared to the uncoated 316 stainless steel. The electrochemical test results also indicate that the ZrC nanoceramic coating shows higher corrosion resistance than the 316 stainless steel under cavitation erosion condition. Thus, the ZrC nanoceramic coating can be adopted to enhance the cavitation erosion resistance of the 316 stainless steel.

scholarly journals Cavitation Erosion Resistance of Laser Beam Nitride Layers of X5CrNi18-10 Stainless Steel

2019 ◽  
Vol 70 (2) ◽  
pp. 708-713 ◽  
Author(s):  
Ilare Bordeasu ◽  
Cornelia Laura Salcianu ◽  
Mircea Octavian Popoviciu ◽  
Ion Mitelea
Keyword(s):  
Stainless Steel ◽  
Laser Beam ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Thermochemical Treatment ◽  
High Hardness ◽  
Basic Material ◽  
Erosion Behavior ◽  
Retaining Ring ◽  
Cavitation Erosion Resistance

The use of nitration in technical applications, as thermochemical treatment, regardless of the used method (ionic, gas or laser beam nitration) is realized to obtain a nitrogen rich layer, which increase the resistance to shock or abrasion, as a result of the high hardness obtained. All the previous cavitation researches showed that hardness is an important mechanical properties, for cavitation erosion resistance increase. The present paper show some results regarding the cavitation erosion behavior of laser beam nitrated layers. As basic material was used the austenitic stainless steel X5CrNi18-10. This material is frequently used for manufacturing details subjected to cavitation, such as valves, drawers of hydraulic distribution and regulation devices, or the retaining ring for butterfly valves. There were used three power regimes of the laser beams: 120 W, 180 W and 240 W. To obtain cavitation erosion was used the standard device with piezo-ceramic crystals of Timisoara Polytechnic University Cavitation Laboratory. The cavitation erosion comparisons, both with the basic material subjected only to the common thermochemical treatments and with the laboratory cavitation standard steel (OH12NDL), show that the nitrated surfaces presents increased cavitation erosion behavior, the principal factor being the important hardness increase of the nitrated layer. We mention also, that for higher laser beam powers the thickness of the nitrated layer increases. All the images obtained at the end of tests show that the cavitation exposure was stopped before overtaking the nitrated layer. So, all our results concern only the hardened layers.

Cavitation erosion resistance of a Co28Cr22Fe alloy.

2017 ◽  
Author(s):  
Juliana Barbarioli ◽  
André Tschiptschin ◽  
Cherlio Scandian ◽  
Manuelle Curbani Romero
Keyword(s):  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Cavitation Erosion Resistance
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