Mean Depth Of Erosion Research Articles

An investigation on the effect of heat input to wear behavior and corrosion-cavitation erosion mechanism of Hastelloy C-276 coating by cold metal transfer

Cold metal transfer (CMT) technology based on wire-arc manufacturing has attracted wide attention because of its advantages of high manufacturing efficiency, low heat input (HI) and near-net-shape. In this study, a CMT-Hastelloy C-276 superalloy surface modification coating by optimizing HI is used to solve the problem of premature failure of key over-flow components of stainless steel in marine engineering. When the HI is increased from 269 J/mm to 358 J/mm, the serious cavitation erosion (CE) damage caused by pore defects and excessive residual tensile stress due to excessive low HI of Hastelloy C-276 coating can be avoid, which is attributed to the effective Orowan strengthening and high proportion of low angle grain bounds (LAGBs: 70.2%). In addition, high contents of Cr, Mo and W elements can promote it's passivation film to maintain excellent self-healing ability during CE to provide continuous and stable protection effect (Rct = 75.68 kΩ·cm2) in the 3.5 wt% NaCl artificial seawater. Therefore, even after 10 h-CE, it still maintains the highest corrosion resistance from both of the thermodynamic (Ecorr = −193.5 ± 3.6 mV) and kinetic perspective (Icorr = 69.3 ± 3.1 μA·cm−2) and has the lowest mean depth erosion rates (MDER, 0.94 ± 0.07 μm/h). However, further increase of HI will cause coarsing of grains (89.6 ± 2.7 μm → 342.8 ± 9.7 μm), excessive precipitation of brittle Mo-rich p phase and excessive dilution of elements from the substrate, resulting in changes in the wear mechanism and deterioration of strength and corrosion resistance. Moreover, the potential of zero charge (PZC) measurements and Mott-Schottky (M-S) test confirmed the decreasing trend of the repulsive ability to Cl ions (ΔE = 0.58 V) and the increased ion doping concentration (ND = 5.94 ± 0.02 × 1022 cm−3) of the weakened n-type passivation films. The optimal combination of wear resistance, corrosion resistance and CE resistance of Hastelloy C-276 coating is obtained by regulating HI, which can lay a theoretical foundation for the related production and application of marine engineering.

Superior resistance to cavitation erosion and corrosion of a novel SiC-reinforced superaustenitic stainless steel coating fabricated by high-velocity air fuel spraying

In this work, we developed a SiC-reinforced superaustenitic stainless steel (SS) coating aimed at enhancing resistance against cavitation erosion (CE) and corrosion. Relevant results indicated that the coating exhibited a diminished mean erosion depth compared to that of 304 SS in 3.5 wt% NaCl solution. Furthermore, a pronounced inhibitory effect on the synergistic interplay between CE and corrosion was demonstrated. Electrochemical assessments underscored the superior passivation and repassivation properties of the coating during CE, contrasting markedly with the compromised passivation capacity of 304 SS, which assumed an active dissolution state characterized by a substantially elevated corrosion current density. The exceptional resistance to CE and corrosion of the coating can be attributed to its low porosity, the elevated levels of corrosion-resistant elements, and the nanoscale grain size. Consequently, this coating emerges as a highly promising candidate for the protective coating on 304 SS flow-handling components.

Effect of synergistic cavitation erosion-corrosion on cavitation damage of CoCrFeNiMn high entropy alloy layer by laser cladding

The CoCrFeNiMn high entropy alloy (HEAs) clad layer was prepared on the surface of 304 stainless steel using coaxial powder feeding laser cladding. The effects of laser energy density on the macroscopic residual stress, crystallographic characteristics, microhardness, corrosion resistance and cavitation erosion (CE) resistance of HEAs clad layer were studied. With the decrease of laser energy density from 45 J/mm2 to 36 J/mm2, pore defects and abnormal coarsening of microstructure in HEAs cladding layer can be effectively avoided, the average grain size can be refined to 74.3 ± 1.7 μm, the average Schmidt factor is 0.43, which also shows the highest dynamic passivation tendency and corrosion resistance in artificial seawater. After 10 h-CE, the carrier density ND in the passivation film of HEAs clad layer can be as low as 3.24 ± 0.08 × 1022 cm−3, and the lowest mean depth erosion rates (MDER) is 0.68 ± 0.07 μm/h, which is much lower than that of 304 stainless steel substrate (4.23 ± 0.13 μm/h). The excellent CE resistance of the HEAs clad layer is attributed to the fact that its grains can effectively resist the plastic deformation and the surface passivation film can maintain a relatively high degree of integrity and continuous level after long aging CE, which has a considerable application prospect in marine engineering.

Correlation between Mechanical Properties—Structural Characteristics and Cavitation Resistance of Rolled Aluminum Alloy Type 5083

The 5000 series aluminum alloy 5083 is distinguished by excellent processability, excellent welding characteristics, and a strong resilience to corrosion, particularly in maritime environments. It is employed in the manufacture of ships, automobiles, spacecraft, and industrial buildings. The goal of the current study is to determine whether there is any relationship between the mechanical properties, structural characteristics, and cavitation erosion properties of aluminum alloy 5083 in the H111 state (rolled from 454 °C to 399 °C and annealed at 343 °C by holding in cooled air), followed by artificial ageing at (180 °C) with three maintenance periods of 1 h, 12 h, and 24 h, and at (140 °C) with three maintenance periods of 1 h, 12 h, and 24 h. The cavitation resistance experiments of the experimental samples were performed in accordance with ASTM G32-2016. The resistance to cavitation erosion was determined by making mean erosion penetration rate (MDER) or mean depth of erosion (MDE) analytical diagrams according to the duration of the cavitation attack and by measuring the maximum depth of cavitation erosion in the samples analyzed by stereomicroscopy and scanning electron microscopy. Finally, a structural correlation between the condition of the artificially aged laminate alloy and its resistance to cavitation erosion could be achieved: ageing at 180 °C, maintained for 24 h, could lead to a maximum depth of cavitation erosion MDEmax of about 5 µm.

The effect of Ni201 transition layer on the corrosion, wear and synergetic cavitation erosion-corrosion behavior of CMT-Monel K500 coating

The Monel K500 modified coating with Ni201 as the transition layer was prepared on the 304 stainless steel substrate by cold metal transfer (CMT) technology. Different from the Monel K500 coatings with direct deposition, the Ni201 transition layer can effectively block the diffusion of Fe and other elements in the substrate and avoid the deterioration of corrosion resistance of Monel K500 coating caused by galvanic corrosion in artificial seawater, which showed the highest polarization resistance and the strongest passivation tendency. In addition, the diffusion of Ni atoms in the transition layer compensated and stabilized the alloy element composition of the Monel K500 coating, making it have a finer microstructure and show higher microhardness and wear resistance. After 10 h- cavitation erosion (CE), the Monel K500 coating with transition layer showed the lowest mean depth erosion rates (MDER) of 2.2 ± 0.09 μm/h as it maintains the highest self-healing ability and integrity of passive film during the long-term synergistic effect of cavitation erosion and corrosion (SCEC). The introduce of the Ni201 transition layer can effectively improve the corrosion-cavitation and wear properties of CMT-Monel K500 surface modified coating, and then effectively prolong the service life of seawater overflow components such as butterfly valves, pump bodies, hydraulic turbines and heat exchangers, which has great application potential in the field of tribo-corrosion in ocean engineering.

Cavitation erosion/corrosion synergy and wear behaviors of nickel-based alloy coatings on 304 stainless steel prepared by cold metal transfer

Inconel 625 and Hastelloy C-276 nickel-based alloy coatings were prepared on 304 stainless steels by cold metal transfer (CMT), aiming at improving the resistance to corrosion, cavitation erosion and wear. The synergistic cavitation erosion-corrosion (SCE-C) effect of the coatings was also revealed in 3.5 wt% NaCl solution. Experimental results show that the Inconel 625 coating was composed of γ-phase matrix and MC-type carbide precipitates dominated by NbC, while the Hastelloy C-276 coating exhibited γ-phase matrix and Mo-rich p phase. Both corrosion resistance and cavitation erosion resistance of the Hastelloy C-276 coating and Inconel 625 coating were higher than that of 304 substrate, and the Hastelloy C-276 coating possessed higher corrosion resistance and cavitation erosion resistance than Inconel 625 coating as indicated by higher polarization resistance (152.95 kΩ cm2) and lower mean depth erosion rates (1.3 ± 0.15 μm/h). The carrier concentration ND of passivation film for Hastelloy C-276 coating (4.05 ± 0.01 × 1022 cm−3) was lower after 10h-cavitation erosion compared to Inconel 625 coating, indicating its passive film showing a stronger passivation behavior and protective ability. The Hastelloy C-276 coating also exhibited a higher wear resistance, and the wear mechanism was adhesive-abrasive comprehensive wear dominated by adhesive wear in the linear reciprocating wear test with Al2O3 as the friction pair. The wear resistance of Inconel 625 coating and Hastelloy C-276 coating was about 1.3 and 1.5 times that of 304 substrate, respectively. The Hastelloy C-276 coating fabricated in the present study exhibited a great potential as flow-passing parts in marine engineering fields due to the desirable resistance to corrosion, cavitation erosion and wear.

Subacromial Erosion After Hook Plate Fixation in Acute Acromioclavicular Joint Dislocation.

To determine the incidence of subacromial erosion, perform quantitative analysis, and identify risk factors after locking hook plate fixation for acute acromioclavicular joint injury. A retrospective case series study. A single tertiary university hospital. The study was conducted on 35 patients who had acute acromioclavicular joint injury. Patients underwent the locking hook plate fixation. The computed tomography (CT) was conducted to measure the subacromial erosion. The acromioclavicular slope (AC slope) of the unaffected side, the acromion-hook angle, the acromioclavicular anteroposterior distance (AC-AP distance), and the preoperative acromioclavicular interval of the affected side were analyzed to identify the risk factors of subacromial erosion. According to the CT findings, subacromial erosion was found in all cases, and the mean value was 5.0 mm, which is 53% of the entire acromion thickness. The AC slope (B = -0.159, P < 0.001) and AC-AP distance (B = 0.233, P = 0.004) were found to have a significant influence on postoperative subacromial erosion. The AC slope showed a negative correlation with the amount of erosion, whereas the AC-AP distance showed a positive correlation with erosion. The CT findings revealed that subacromial erosion occurred in all cases, and the mean erosion depth was about 50% of the acromial thickness. If the preoperative AC slope of the unaffected side was more acute and the AC-AP distance was larger, the incidence of subacromial erosion was higher. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Assessment of flow aggressiveness and erosion damage topography for different gap widths in ultrasonic cavitation testing

Incubation time and erosion rate of C15 steel (SAE 1016) are measured in a cavitation test-rig utilizing an ultrasonic horn. The gap width (separation distance) between horn tip and stationary sample is varied and effects on material damage are studied. Cavitation erosion shows a local maximum for a gap width of 0.5 mm at the stationary specimen, while it continuously rises on the horn tip with rising gap width. A characteristic erosion pattern develops at horn tip and stationary specimen. By a-posteriori surface erosion topography measurements, radial erosion depth profiles are evaluated. Together with scanning electron microscopy investigations, they provide information on the spatial distribution of the flow aggressiveness and on wear mechanisms. By means of computational fluid dynamics (CFD) results, the local surface erosion topography is associated to harmonic and subharmonic collapse events within the gap. Pressure measurements have been performed by piezoelectric polyvinylidene fluoride (PVDF) sensors, mounted in central as well as eccentric position on the specimen surface. A local mean of the erosion depth profile is evaluated on the surface portion that corresponds to the PVDF sensor locations. By temporally high-resolved pressure data, a cumulative force load is evaluated. For larger gap width, a good correlation of cumulative force load with the inverse incubation time, erosion rate, as well as mean erosion depth is obtained, while for the smallest gap width of 0.3 mm, the correlation deteriorates.

Effect of pearlitic morphology with varying fineness on the cavitation erosion behavior of eutectoid rail steel

The present work discusses the effect of the pearlitic morphology with varying fineness on the cavitation erosion behavior of eutectoid rail steel. Cavitation erosion of three different types of the pearlitic steels (furnace-cooled, air-cooled, and forced-air-cooled) consisting of coarse, fine, and very fine microstructures were tested in 3.5% NaCl solution and compared with that of the as-received pearlitic rail steel. The variation in the mean depth of erosion (MDE) and mean depth erosion rate (MDER) with erosion time was analyzed. Furthermore, the cavitation erosion resistance of the as-received, the air-cooled, and the forced-air-cooled was found to be 1.03, 1.51, and 2.14 times better than the furnace-cooled pearlitic steel, respectively. It was concluded that the cavitation erosion resistance of the pearlitic steel increased with the increase in the fineness of the microstructure.

Complex concentrated alloy bimodal composite claddings with enhanced cavitation erosion resistance

In this current study, we developed SiC (10 wt%) reinforced AlCoCrFeNi complex concentrated alloy composite claddings with different particle sizes (micro, nano and bimodal) on stainless steel 316L substrate using microwave irradiation. Microstructural analysis showed cellular structured claddings with intermetallic phases occupying the intercellular regions along with low porosity (<1%). The claddings were mainly composed of A2 (disordered BCC) and B2 (ordered BCC) along with Cr23C6. The bimodal (mixture of nano and micro) composite cladding showed highest hardness and fracture toughness (810 HV and ~12.2 MPa√m) followed by nano and micro composite claddings. Under cavitation erosion (distilled water) condition, bimodal cladding showed highest incubation period (IP) (~13 h) with extremely low mean depth erosion rate (MDER) (~0.089 μm/h) with 16 and 27 times lower than stainless steel 316L and WC-based coating, respectively. The cavitation erosion resistance observed for the bimodal composite cladding is among the highest demonstrated by the CCAs at present. However, under erosion-corrosion conditions, non-reinforced and micro-reinforced claddings showed higher degradation resistance with lower material removal rates than that observed for bimodal cladding. Standalone electrochemical corrosion studies also showed highest corrosion and passivation resistance for non-reinforced cladding. These results were explained on the basis of formation of Cr-depleted micro-galvanic cells due to high negative enthalpy of Cr with C dissociated from SiC particle. The detailed morphological analysis of the tested samples showed presence of tearing top surface as the primary degrading mechanism along with fracture of intermetallic phases. The results show that bimodal composite CCA cladding provides a potential surface engineering solution for improvising the serviceability of the many engineering systems.

Investigation on ultrasonic cavitation erosion of TiMo and TiNb alloys in sulfuric acid solution.

Two kinds of Ti-alloys, i.e., TiMo and TiNb alloys are manufactured in this paper, and their ultrasonic cavitation erosion behaviors in 0.1M H2SO4 solution are evaluated by the mean depth erosion (MDE), SEM and white light photograph. The results show that MDE of TiMo and TiNb alloys obviously increase with increasing the cavitation erosion time, however, they evidently decrease with the increment of Mo or Nb content at each fixed cavitation erosion time, and even some large blank areas (uneroded areas) still exist on the sample surface after ultrasonic cavitation erosion for 2h in the case of Ti10Mo and Ti20Nb samples, implying the enhanced anti-cavitation erosion property of Ti-alloy by adding Mo or Nb element. The MDE of Ti10Mo or Ti20Nb sample is lower than that of TC4 sample in the case of each cavitation erosion time, indicating the better cavitation erosion resistance of of Ti10Mo or Ti20Nb sample. The influences of Mo and Nb on the passivity of TiMo and TiNb alloys during the ultrasonic cavitation erosion are detected by potentiodynamic curves. The results display that Ti, TC4, TixMo (x=1, 5, 10) and TixNb (x=5, 10, 20) samples are all almost in the passive state within the potential region from 0VSCE to 1.5VSCE during ultrasonic cavitation erosion, and the passive current density evidently decreases with increasing Mo or Nb content, indicating the enhanced passive characteristic by adding Mo or Nb alloys during the ultrasonic cavitation erosion.

Cavitation erosion of glass fibre reinforced polymer composites with unidirectional layup

Glass fibre reinforced polymer (GFRP) composites are increasingly used in marine applications and can be subjected to aggressive environmental effects, one of which is cavitation. This study investigates the behaviour of unidirectional GFRP composites exposed to cavitation erosion generated using an ultrasonic transducer. Cavitation erosion tests were performed in accordance with the ASTM G32 standard. All specimens were preconditioned to eliminate the influence of water absorption on the mass loss caused by cavitation. The erosion process was monitored with a microscope and the mass loss was measured at regular periods. The tested specimens were scanned with X-ray computed microtomography. The research findings indicated that the erosion process was affected by several parameters including specimen thickness, distance between fibre bundles, bundle shape and distribution. The initiation and development of erosion damage were highly influenced by the surface condition. Cavitation erosion traced parts of fibre bundles located closer to the surface creating trenches and valleys on the surface. The regions with thick epoxy layers above and between fibre bundles were much less susceptible to erosion damage. Several erosion mechanisms were identified and discussed. The research findings also highlighted the difficulties in characterising ultrasonic cavitation erosion of GFRP composites using acoustic impedance and mean erosion depth.

Cavitation Damage Prediction of Stainless Steels Using an Artificial Neural Network Approach

Cavitation damage has not been well predicted because of its complex relationship of many mechanical and microstructural factors. An artificial neural network approach of the back-propagation network was used to predict cavitation damage of stainless steels, 316L and 420, in terms of the significant influence of cavitation time, roughness, and residual stress on cavitation damage. Mean depth of erosion was used to quantitatively describe cavitation damage of 316L and 420. Prediction accuracy was improved by analyzing the effects of the number and type of input nodes, the number of nodes in the hidden layer, and different activation functions on prediction accuracy. The best performance was in the model with the input nodes of cavitation time and roughness, eleven nodes in the hidden layer, and the activation function of logsig.

Cavitation erosion – corrosion behavior of some hydraulic turbine runner steels

Cavitation erosion is still a phenomenon which causes severe damages to hydraulic turbine runners. A lot of effort has been deployed in the scientific community to understand the materials response to this kind of solicitation. Part of researches which are conducted at Research Institute of Hydro-Quebec are focused on determining the materials behavior laws. For this, the classical ASTM G32 standard is used. Mass losses are followed during the exposure time. Also degradation parameters i.e mean depth of erosion and erosion rate are determined. Furthermore, a lot of effort has gone into the determination of the evolution of surface damages in terms of pitting, surface cracking and material removal. For this, microscopy techniques have been used to link the microstructure to the material removal mechanisms. Furthermore, another part of the researches is focused on enlightening and quantifying the deleterious effect of the environment. In some cases, a synergistic effect can establish between cavitation erosion mechanisms and corrosion kinetics and increase the material degradation. In the present study the ultrasonic cavitation rig has been coupled with electrochemical techniques to determine the contribution of corrosion to this phenomenon in natural river freshwater. The electrochemical behavior of three commonly used materials in hydraulic turbine runners, ASTM A27, E309L and UNS S41500 are studied in condition of quiescence and also in cavitation conditions.

Considerations regarding the erosion mechanism of vibratory cavitation

The cavitation erosion researches conducted on vibratory devices presents a way of degradation very similar with those encountered in industrial equipment. Photos of the cavitation cloud as well as the eroded surfaces, at various exposure periods, are the basis of the present work in the description of this destruction mechanism. For the experiments, there were used two materials: gray cast iron with lamellar graphite and a high resistance bronze. The used device is that of the Timisoara Polytechnic University Cavitation Laboratory which respects integrally the prescriptions of ASTM G32-2010 Standards. For the description of the results there are used both the roughness profiles and the structure images of the eroded areas, after four different exposure times (5, 60, 120 and 165 minutes). The cavitation erosion behavior is expressed both by the mean depth erosion (MDE) and the parameters of roughness values of the affected areas. The conclusion show that the specific degradation is determined by the cavitation hydrodynamics, as well as by the repeated implosion of individual bubbles which forms the cavitation cloud attached to the exposed surface.

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

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.

The use of Rz roughness parameter for evaluation of materials behavior to cavitation erosion

It is well known that the cavitation eroded surfaces have a porous appearance with a pronounced roughness. The cause is the pitting resulted from the impact with the micro jets as well as the shock waves both determined by the implosion of cavitation bubbles. The height and the shape of roughness is undoubtedly an expression of the resistance of the surface to the cavitation stresses. The paper put into evidence the possibility of using the roughness parameter Rz for estimating the material resistance to cavitation phenomena. For this purpose, the mean depth erosion penetration (MDE-parameter, recommended by the ASTM G32-2010 Standard) was compared with the roughness of three different materials (an annealed bronze, the same bronze subjected to quenching and an annealed alloyed steel), both measured at four cavitation erosion exposure (30, 75, 120 and 165 minutes). The roughness measurements were made in 18 different zones, disposed after two perpendicular diameters, along a measuring lengths of 4 mm. The results confirm the possibility of using the parameter Rz for estimating the cavitation erosion resistance of a material. The differences between the measured values of Rz and those of the characteristic parameter MDE are of the same order of magnitude as those obtained for MDE determination, using more samples of the same material.

Cavitation erosion of 17-4 PH stainless steels following sub-zero treatment

Abstract The effect of sub-zero treatment on 17-4 PH stainless steels is analysed based on ultrasonic cavitation experiments conducted on a vibratory machine with piezoceramic crystals. The results prove that the proposed treatment (solution treatment + sub-zero cooling + tempering), favours a reduction, by about 40%, of the mean depth of erosion, and mean depth erosion rate after 165 min of erosion by vibratory cavitation, compared to the solution treatment. The improvement of the cavitation erosion behaviour is explained based on hardness, metallographic and X-ray diffraction analysis.

A New Model for the Equation Describing the Cavitation Mean Depth Erosion Rate Curve

Paper present a new relation describing the curve MDER(t) which mediates the experimentally obtained values of the mean depth erosion rates. These curves are used to characterize the cavitation erosion behavioor of materials tested in the Cavitation Laboratory of Timisoara Polytechnic University. Practically the new relation is an improvement of the analytical model established in 2004 by Bordeasu and coworkers, by introducing a supplementary element, which take into consideration the shape of the zone in where the cavitation erosion rate became stable and has linear variation. These addition allow increasing the approximation of the experimental values and also putting into evidence the tiny differences between different materials (various types of stainless steels, highly alloyed bronzes etc.) which till now were considered with similar resistance. Thus, the supplementary term allow a better differentiation resulting from the chemical composition, the structure and the mechanical properties.

A new concept for stainless steels ranking upon the resistance to cavitation erosion

In present, the ranking of materials as their resistance to cavitation erosion is obtained by using laboratory tests finalized with the characteristic curves mean depth erosion against time MDE(t) and mean depth erosion rate against time MDER(t). In some previous papers, Bordeasu and co-workers give procedures to establish exponential equation representing the curves, with minimum scatter of the experimental obtained results. For a given material, both exponential equations MDE(t) and MDER(t) have the same values for the parameters of scale and for the shape one. For the ranking of materials is sometimes important to establish single figure. Till now in Timisoara Polytechnic University Cavitation Laboratory were used three such numbers: the stable value of the curve MDER(t), the resistance to cavitation erosion (Rcav ≡ 1/MDERstable) and the normalized cavitation resistance Rns which is the rate between vs = MDERstable for the analyzed material and vse= MDERse the mean depth erosion rate for the steel OH12NDL (Rns = vs/vse ). OH12NDL is a material used for manufacturing the blades of numerous Kaplan turbines in Romania for which both cavitation erosion laboratory tests and field measurements of cavitation erosions are available. In the present paper we recommend a new method for ranking the materials upon cavitation erosion resistance. This method uses the scale and shape parameters of the exponential equations which represents the characteristic cavitation erosion curves. Till now the method was applied only for stainless steels. The experimental results show that the scale parameter represents an excellent method for ranking the stainless steels. In the future this kind of ranking will be tested also for other materials especially for bronzes used for manufacturing ship propellers.