EROSION WEAR OF SOLID PARTICLES IN 317 STAINLESS STEEL

Transcription

1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 7, July 2017, pp , Article ID: IJMET_08_07_193 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed EROSION WEAR OF SOLID PARTICLES IN 317 STAINLESS STEEL Ravi Kumar Assistant Professor, School of Mechanical Engineering, Akhil Nandu School of Mechanical Engineering, Dr. S.K. Kumaraswamy ICMCB, CNRS, Bordeaux, France. Dr. Uday Krishna Ravella School of Mechanical Engineering, Dr. Anil Midathda School of Mechanical Engineering, ABSTRACT In this work, stainless steel 317 is selected as base metal. Slurry erosion tests are carried out to examine the wear performance of the AISI 317 stainless steel. The erodent particles used are normal sand with size of µm in the experimental work. The experiments are carries out using various impact angles (30, 45, 60 and 90 ) with different velocity (8 m/sec and 14 m/sec) and an erodent flow rate of 150±0.5 g/min. The particles concentration and testing time are kept constant throughout the slurry erosion test. The tests are carried out 1.5 min per sample for each testing. The temperature of test solution was maintained at room temperature throughout the experiments. SEM images are used to analyze the surface wear mechanics of the components. The SEM results showed the higher erosion rate at the 60 impact angle and minimum at 30. The material wear is higher in untreated specimens and less in cryogenic treatment specimen. Key words: Stainless Steel, Slurry Erosion, Microstructure, SEM. Cite this Article: Ravi Kumar, Akhil Nandu, Dr. S.K. Kumaraswamy, Dr. Uday Krishna Ravella and Dr. Anil Midathda Erosion Wear of Solid Particles In editor@iaeme.com

2 Erosion Wear of Solid Particles In 317 Stainless Steel Stainless Steel. International Journal of Mechanical Engineering and Technology, 8(7), 2017, pp INTRODUCTION Erosion is a serious material wear problem in many engineering applications such as regenerators, air mills, refinery, gas turbine etc. Removal of material by the action of solid particle is known as the erosion wear. Erosion is basically degradation of surface of the impact of very small size particles on the component surface. Erosion wear occurs due to relative motion with respect to another substance. In the wearing process, material loss and dimensional changes occurs, which results plastic deformation. Erosion process depends upon many factors such as particle velocity, impact angle, particle concentration, particle shape and size etc. [2, 3]. Hutchings [4] examined that many forces such as contact force, drag force, inter-particle contact force and gravity force etc. were acted on a particle when it meets other particles or surfaces. Finnie s [5] erosion model was used extensively for erosion wear mechanism for both brittle and ductile materials. Hutchings and Finnie s both solved the erosion problem in ductile material at normal and oblique impact angle. The material is plastically deformed in the form of debris around the indentation component. In slurry erosion process particles are entrained in the fluid medium [1]. Material wear occurs by the action of repeated. 2. METHODOLOGY 2.1 Selection of base metal Stainless steel grade 317 is mostly used in chemical component which has better erosion corrosion than others lower grades. The specimens are square in shape with dimension of 20 mm length, 20 mm width and 6.5 mm in thickness. Chemical composition of SS 317 is given in Table 1. Table 1 Chemical composition of stainless steel 317 Cr Ni Mo Mn S P Si C Fe Bal. Table 2 Parameters for Erosion test Particle velocity 8m/sec,14m/sec Impact angle 30,45,60,90 Time Sand Particle size Temperature 1.5 min microns Ambient temp. 2.2 Test to be performed Erosion test was performed using jet type erosion test rig. For this sample was prepared as per ASTM standard having size 20mm X 20mm X 6.5mm as shown in Figure 1. Figure 2 shows the mounting of sample as holder and nozzle for impingement of particles on sample. Water and sand particle are premixed in the feed hopper by using stirrer controllable device. For each sample tests 150 ± 0.5 g sand is taken. The test was carried out for 1.5 min for each editor@iaeme.com

3 Ravi Kumar, Akhil Nandu, Dr. S.K. Kumaraswamy, Dr. Uday Krishna Ravella and Dr. Anil Midathda sample. The weighing of sand is done by using precision weighing balance with a least count of 0.1 gram. The erosion tests are carried at different impingement angle and flow velocity of the fluid mixture. 30, 45, 60 and 90 angles are considered in this experiment at the velocity of 8m/sec and 14 m/sec. for each specimen. The concentration and time were kept constant throughout the slurry erosion test. The temperature of test solution was maintained at room temperature throughout the experiments. The erosion test was performed in IIT Ropar. The parameters for test are given in table II. Surface morphology was investigated using Optical microscope and scanning electron Microscope (SEM) to analyze the surface behavior. Optical microscope was used for Microstructural observations at magnification of 100X taken at Lovely University, Phagwara (Punjab). Before the observations, the samples were ground, polished and etched with 3% Nital for 15 seconds. SEM was performed at SAI labs Thapar University Patiala. Figure 1 Sample pieces Figure 2 Sample holder and nozzle 3. EXPERIMENTAL RESULTS 3.1. Erosion test Results were obtained from the erosion test at velocity 14 m/sec. are given in Table 3 and their plot is shown in figure 4 The weight loss method was adopted for calculating wear. Initial weight of the sample was measured and after completion of 1.5 min further weight was measured. Figure 3 is showing the plot between the impact angle and Avg. erosion rate. The result obtained at velocity 8 m/sec. is given in Table 4.The erosion wear rate of the samples are higher when velocity is 14 m/sec whereas when velocity is 8 m/sec., the erosion wear rate decreases. The material removal is high at the specimen angle 60 and 45 and minimum at the specimen angle 30. S. No Angle ( ) Table 3 Result of Untreated Specimen at velocity of 14 m/sec Normal Weight(g) Avg. weight of tested sample (g) Material wear of sample (g) Avg. erosion rate(g/g) 10-5 Table 4 Result of Untreated Specimen at velocity of 8 m/sec editor@iaeme.com

4 Erosion Wear of Solid Particles In 317 Stainless Steel S. No. Angle ( ) Normal Weight(g) Avg. weight of tested sample(g) Material wear of sample (g) 10-3 Avg. erosion rate (g/g) Figure 3 Plot b/w impact angle and Avg. erosion rate Figure 4 Plot b/w impact angle and Avg. erosion rate 3.2. Optical Microscope The microstructure of SS 317 is shown in Figure 5 and Figure 6 for untreated and treated samples respectively. Austenitic and ferrite phase are present in SS 317. Grain boundary and secondary austenite are also present. After the cryogenic treatment, the presence of retained austenite is decreased. In deep cryogenic treatment, the more number of retained austenite changed intomartensite. Carbon clustering decreases due to lesser the carbon density with each cycle of deep cryogenic treatment which causes increase in hardness with each cycle. The resulting grain microstructure gets more refined with cycle of deep cryogenic treatment. It is obtained that the cryogenic treatment provides the better stability, wear resistance, improved fatigue life and minimized residual stresses. Figure 5 Microstructure of untreated SS317 Figure 6 Microstructure of cryogenic treated SS317L editor@iaeme.com

5 Ravi Kumar, Akhil Nandu, Dr. S.K. Kumaraswamy, Dr. Uday Krishna Ravella and Dr. Anil Midathda 3.3. Scanning Electron Microscope Figure 7-10 shows the eroded surface wear of material at the impingement angle 30, 45, 60, 90. The wear scars are increases at the higher impact angles. In Figure. 7-8, scratches and ploughing action are observed. SEM image of AISI 317 at 30 show wear debris, which is less as compared to the 60 and 90. Material wear are low at 30 and 45 but higher at 60 at 90 impact angle. The Material removal rate is non-uniform throughout the surface at different impingement angle. Wear debris, ploughing action, displaced material and cavities are shown in the images. In Figure. 9-10, the cryogenic treated sample are used for the erosion phenomenon at different angles. In the Figure. 10 the wear rate is very less as compared to others treated samples. At Maximum erosion wear rate occurs in the untreated samples and it reduces after the cryogenic treatment of the sample. Wear debris, scars, cracks and cavities etc. are very less in the cryogenic treated specimens and maximum in the untreated specimens. Figure 7 SEM image of untreated sample wear at impact angle of 30 and 45 respectively Figure 8 SEM image of untreated sample wear at impact angle of 60 and 90 Figure 9 SEM image of Cryogenic treated sample wear at impact angle 30 and editor@iaeme.com

6 Erosion Wear of Solid Particles In 317 Stainless Steel Figure 10 SEM image of Cryogenic treated sample wear at impact angle 60 and CONCLUSION 1. Erosion wear depends on the particle concentration and their attacking angle. 2. Maximum erosion wear occurs at the 60 impingement angle of the specimen 3. On increasing the velocity the rate of material wear also increases. 4. After cryogenic treatment material removal rate of the specimens decreases. 5. The material is deformed in brittle nature and produces rougher surface. 5. REFERENCES [1] Sundararajan, G., and Manish Roy. Solid particle erosion behavior of metallic material at room and elevated temperatures. Tribology International 30.5 (1997): [2] H. Mcl. Clark, The influence of the flow field in slurry erosion, Wear 152(1992) [3] J.A.C. Humphrey, Fundamentals of fluid motion in erosion by solid particle impact, Int. J. Heat Fluid Flow 11(1990) [4] Andreska, Jannis, Christoph Maurer, and Jens Bohnet Erosion resistance of electroplated nickel coatings on carbon-fiber reinforced plastics. Wear (2014): [5] Patnaik, A., Satapathy, A., Chand, N., Barkoula, N. M., & Biswas, S. (2010). Solid particle erosion wears characteristics of fiber and particulate filled polymer composites: A review. Wear, 268(1), [6] Dube, Narendra M, Anirudh Dube, Deepak H. Veeregowda, and Suman B. Iyer Experimental technique to analyse the slurry erosion wear due to turbulence. Wear 267, no. 1 (2009): [7] Shimizu, K., T. Naruse, Y. Xinba, K. Kimura, K. Minami, and H. Matsumoto Erosive wear properties of high V Cr Ni stainless spheroidal carbides cast iron at high temperature. Wear 267, no. 1 (2009): [8] Harsha, A. P., and Avinash A. Thakre Investigation on solid particle erosion behavior of Polyetherimide and its composites Wear 262, no. 7 (2007): [9] Harsha, A. P., and Sanjeev Kumar Jha Erosive wear studies of epoxy-based composites at normal incidence. Wear 265, no. 7 (2008): [10] Wood, R. J. K., J. C. Walker, T. J. Harvey, S. Wang, and S. S. Rajahram Influence of microstructure on the erosion and erosion corrosion characteristics of 316 stainless steel. Wear 306, no. 1 (2013): [11] Nguyen, V. B., Q. B. Nguyen, Z. G. Liu, S. Wan, C. Y. H. Lim, and Y. W. Zhang A combined numerical experimental study on the effect of surface evolution on the water sand multiphase flow characteristics and the material erosion behavior. Wear 319, no. 1 (2014): Nwoke H.U, Dike B.U, Okoro B.C, Nwite S.A, Uprooting Resistance and editor@iaeme.com

7 Ravi Kumar, Akhil Nandu, Dr. S.K. Kumaraswamy, Dr. Uday Krishna Ravella and Dr. Anil Midathda Morphological Traits of Plants Used In Erosion Mitigation, International Journal of Civil Engineering and Technology, 7(3), 2016, pp [12] Jafar, R. Haj Mohammad, J. K. Spelt, and M. Papini Surface roughness and erosion rate of abrasive jet micro-machined channels: experiments and analytical model. Wear 303, no. 1 (2013): editor@iaeme.com