Wear Behavior of Laser Surface-Hardened Gray and Ductile Cast Irons. Part 2—Erosive Wear

1988 ◽  
Vol 110 (3) ◽  
pp. 462-466 ◽  
Author(s):  
P. A. Molian ◽  
Mark Baldwin
Keyword(s):  
Erosion Rate ◽  
Continuous Wave ◽  
Wear Behavior ◽  
Surface Hardness ◽  
Erosive Wear ◽  
Gray Iron ◽  
Case Depth ◽  
Cast Irons ◽  
Beneficial Effects ◽  
Erosion Mechanisms

A 1.2-kW, continuous wave, CO2-gas laser was used to transformation harden or melt the surface of gray and ductile cast irons. Effects of surface-hardened layers on solid particle erosion showed that the erosion rate decreased with an increase in surface hardness and case depth. The order of matrix microstructures that increased the erosion rate were ledeburite, tempered martensite, and pearlite. These results were opposite to those observed in bulk-hardened alloys. Erosion mechanisms of brittle, gray iron included micromachining in the untreated condition and grain boundary cracking in the laser-treated condition. In contrast, erosion modes of ductile iron were plastic flow followed by cracking in the untreated condition and platelet formation and fatigue in the laser-treated conditions. The beneficial effects of surface hardening on erosion were examined and discussed.

Wear Behavior of Laser Surface-Hardened Gray and Ductile Cast Irons: Part 1—Sliding Wear

1986 ◽  
Vol 108 (3) ◽  
pp. 326-333 ◽  
Author(s):  
P. A. Molian ◽  
Mark Baldwin
Keyword(s):  
Sliding Wear ◽  
Continuous Wave ◽  
Wear Behavior ◽  
Test System ◽  
Case Depth ◽  
Laser Surface ◽  
Dramatic Improvement ◽  
Cast Irons ◽  
Severe Wear ◽  
Depth Analysis

The influence of laser surface transformation hardening on the sliding wear characteristics and mechanisms of ASTM class-40 gray and 80-55-06 ductile cast irons was investigated. A 1.2 kw, continuous wave, CO2 gas laser was employed to scan the beam successively across the surfaces of cast irons to generate hardened and tempered layers with various case depths. A pin-on-disk wear test system was then used to study the wear behavior as functions of case depth, microstructure, hardness, and surface roughness. As expected, a dramatic improvement in resistance to scuffing and sliding wear was obtained. However, the most significant result was the occurrence of negligible oxidational wear for a load range that increased with an increase in case depth. Resistance to mild and severe wear, mild-to-severe wear transition load, and frictional heating were increased with an increase in case depth. Analysis of worn surfaces and wear debris revealed that negligible oxidational wear in laser-hardened irons is due to two mechanisms: oxidation and adhesion of oxide to the substrate. In contrast, the mild oxidational wear of untreated irons occurs through the formation of loose oxide debris. The mechanisms of severe wear were plastic deformation, delamination, and adhesion; the rate process was controlled by adhesion for laser hardened irons and delamination for untreated irons.

Laser Heat Treatment of Cast Irons—Optimization of Process Variables, Part II

1986 ◽  
Vol 108 (3) ◽  
pp. 233-239 ◽  
Author(s):  
P. A. Molian ◽  
A. K. Mathur
Keyword(s):  
Gaussian Beam ◽  
Laser Power ◽  
Thermal Response ◽  
Rate Distortion ◽  
Theoretical Models ◽  
Gray Iron ◽  
Case Depth ◽  
Coverage Rate ◽  
Cast Irons ◽  
Heat Treated

ASTM class 40 gray and 80-55-06 ductile cast irons were surface heat-treated by a 1.2-kW, CO2 laser to study the effects of square and oscillating-gaussian beam modes on case depth, coverage rate, distortion, hardness, and microstructure. The results were compared with that of ring and gaussian beam modes, which were described in Part I. Square and oscillating beams maximized case depth and coverage rate, while ring and gaussian beams minimized distortion. Hardness and microstructure of heat-treated layers were unaffected by the beam mode. For given laser parameters, ductile iron always exhibited larger case depth and coverage rate than gray iron because of the lower thermal diffusivity. Experimental data and theoretical models indicated that thermal response of a material to laser power cannot be described by a simple function as given by heat conduction models and that the best correlating factor for case depth is P/V (P is laser power, V is scan rate).

COMPUTATIONAL OPTIMIZATION OF TiO2 FILLED A384 ALLOY COMPOSITES IN EROSIVE ENVIRONMENT

2012 ◽  
Vol 01 (03) ◽  
pp. 1250025 ◽  
Author(s):  
SWATI GANGWAR ◽  
VIKAS KUKSHAL ◽  
AMAR PATNAIK ◽  
TEJ SINGH
Keyword(s):  
Erosion Rate ◽  
Filler Content ◽  
Wear Behavior ◽  
Optimization Technique ◽  
Erosive Wear ◽  
Stir Casting ◽  
Impingement Angle ◽  
Casting Technique ◽  
Computational Optimization ◽  
Order Preference

In this article, micro and nano titania ( TiO2 ) filled A384 alloy composites are fabricated by stir casting technique with varying filler content from 0–8 wt.% respectively and then we study their physical, mechanical, thermal and erosive wear characteristics respectively. Effect of impact velocity (25–70 m/sec) and impingement angle (30°–90°) on erosion wear behavior of micro and nano TiO2 filled A384 alloy has also been studied. Finally, an optimization technique was implemented in order to develop a correlation between the physical, mechanical and erosion rate of TiO2 filled A384 alloy composites by using technique order preference by similarity to ideal solution (TOPSIS).

Fatigue Characteristics of Laser Surface-Hardened Cast Irons

1987 ◽  
Vol 109 (3) ◽  
pp. 179-187 ◽  
Author(s):  
P. A. Molian
Keyword(s):  
Continuous Wave ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Case Depth ◽  
Laser Surface ◽  
Low Alloy Steels ◽  
Surface Layers ◽  
Cast Irons ◽  
Co2 Gas ◽  
Alloy Steels

Contrary to expectations, laser surface heat treatment has a deleterious effect on the fatigue performance of pearlitic gray and ductile cast irons. A 1.2 kW, continuous wave, CO2 gas laser, operating in square beam mode, was employed to heat-treat the surfaces of standard fatigue specimens. Rotational-bending fatigue tests were then conducted on untreated (as-cast) and laser treated specimens. Results indicated that the effect on fatigue behavior of case depth, microstructure and hardness of laser-hardened surface layers were opposite to that observed in carbon and low alloy steels. A fracture model based on the presence of graphite, residual stresses, and strain-induced transformation is postulated to explain the adverse effect of laser hardening of cast irons.

scholarly journals Dry Sliding Wear Behavior of Austenitic Stainless Steel Material by Gas Nitriding Process

2021 ◽  
Vol 309 ◽  
pp. 01181
Author(s):  
K. Ramya Sree ◽  
D. Raguraman ◽  
J. Saranya ◽  
Animesh Bain ◽  
V. Srinivas Viswanth ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Wear Behavior ◽  
Surface Hardness ◽  
Case Depth ◽  
Nitriding Process ◽  
Dry Sliding Wear ◽  
Low Carbon ◽  
Wear Properties ◽  
Gas Nitriding ◽  
Steel Material

In industries, components must operate under extreme conditions such as high load, speed, temperature and chemical environment. Materials are selected according to commercial availability, cost and their properties such as strength, hardness, etc. AISI 904L is a high-alloy stainless steel with low carbon content, poor surface hardness and wear characteristics. Many engineering failures are caused by fatigue, corrosion, and poor wear resistance, begins at the surface level. This causes cracks in the surface, reducing the material’s life. The surfaces of the materials were subjected to severe thermal, chemical, and shock loads. The selected AISI 904L materials for this work were subjected to gas nitriding process and processed with 3 different time parameters such as 12 hours, 18 hours and 24 hours respectively and named as GN1, GN2 and GN3. The treatments were done at a constant temperature of 650°C. Gas nitriding, in comparison to other nitriding processes such as plasma and liquid nitriding, provides good dimensional stability, reduced deformation, and uniform case depth regardless of the size and shape of the specimen. To analyze the wear properties, a pin on a disc machine is used. Finally, metallographic studies were performed by scanning electron microscopy.

G0400405 Influence of shape of WC on erosive wear behavior of cast-in insertion cast irons

2015 ◽  
Vol 2015 (0) ◽  
pp. _G0400405--_G0400405-
Author(s):  
Kimitoshi NAKAMURA ◽  
Kazumichi SHIMIZU ◽  
Kenta KUSUMOTO
Keyword(s):  
Wear Behavior ◽  
Erosive Wear ◽  
Cast Irons

scholarly journals Application of DCT and Weld Harfacing for Enhancing Erosion Resistance of PCBN: A Review

2018 ◽  
Vol 7 (2) ◽  
pp. 154-159
Author(s):  
Puneet Pal Singh ◽  
Pardeep Kumar
Keyword(s):  
Erosion Resistance ◽  
Cryogenic Treatment ◽  
Thermal Power ◽  
Surface Hardness ◽  
Erosive Wear ◽  
Current Status ◽  
Material Degradation ◽  
Cast Irons ◽  
Deep Cryogenic Treatment ◽  
Power Generation Plant

Solid particle erosion (SPE) is a dominating material removal process in various industries which contributes to material degradation of wide variety of engineering tools and components. Literature evidences the efforts made to capture the material degradation problem due to SPE. Enhancement of mechanical properties like hardness with sufficient ductility is prerequisite of erosion resistance. But it is difficult to improve conflicting properties such as hardness and ductility at the same time. Hardfacing is an effective method to extend the service life of machine components experiencing abrasive, corrosive or erosive wear, by increasing surface hardness without affecting the ductility of the base metal. It can be done with the help of various welding techniques, depending upon the prevailing conditions, requirements and desired results. Submerged arc welding (SAW) provides large deposit rates with ease of automation. Heat treatment is a conventional process, which is used since long times to alter different properties of materials according to the requirements. Deep cryogenic treatment (DCT) followed by a subsequent tempering process has also reported to produce interestingly positive results by improving hardness, toughness and erosive wear resistance of tool steels, carburized steels and cast irons. This paper reviews the current status of literature exhibiting the use of DCT in tackling the problem of SPE and its proposed use in improving erosion resistance of pulverized coal burner nozzles (PCBN’s) used in thermal power generation plant.

Investigation on Effect of Fibre Volume and Fiber Orientation on Erosive Wear Behavior of Carbon Fiber Reinforced Epoxy (CFRP) Composites

2019 ◽  
Vol 969 ◽  
pp. 134-139 ◽  
Author(s):  
Mylarapu Kameswara Reddy ◽  
V. Suresh Babu ◽  
K.V. Sai Srinadh
Keyword(s):  
Polymer Composites ◽  
Fiber Orientation ◽  
Erosion Rate ◽  
Epoxy Polymer ◽  
Wear Behavior ◽  
Erosive Wear ◽  
Processing Parameters ◽  
Fibre Volume ◽  
Wear Properties ◽  
Fiber Volume

This paper investigates erosive wear properties of carbon-epoxy polymer composites. Hand layup technique was employed to fabricate the composite specimens. Sand erosion properties of carbon/epoxy polymer composites were examined by changing testing parameters such as varying angle of impact (300,450,600 and 900), velocity of impact of sand particles (48m/s and 70m/s) and Stand-Off distance (5mm and10mm); and also by changing composite processing parameters such as fiber volume (20%, 25%, and 30%) and fiber orientation (300,600 and 900). Irrespective of fiber volume and fiber orientation, rate of erosion shows increasing tendency, with increase of impact velocity. It was observed that with increase in fiber volume, erosion rate increases and where fiber orientation is concerned, increase of fiber orientation leads to increase in erosion rate. Irrespective of fiber orientation and fiber volume, Increase of Stand-Off distance leads to decrease in erosion rate. Finally the eroded surface morphology was observed by using SEM.

Effect of Nano TiO2/Clay on the Erosive Wear Behavior of Basalt-Epoxy Hybrid Composites at Elevated Temperatures

2015 ◽  
Vol 813-814 ◽  
pp. 40-45 ◽  
Author(s):  
C R Mahesha ◽  
Shivarudraiah ◽  
C. Rajesh Chandra ◽  
R. Suprabha
Keyword(s):  
Impact Velocity ◽  
Erosion Rate ◽  
Elevated Temperatures ◽  
Hybrid Composites ◽  
Wear Behavior ◽  
Erosive Wear ◽  
Wear Test ◽  
Normal Incidence ◽  
Filler Concentration ◽  
The Impact

Materials added to the matrix help improving operating properties of a composite. In the last few years, nanofiller /polymer composite have been widely investigated because of their outstanding multifunctional properties. In order to improve the erosive wear resistance of composite, an attempt was made to use nanoTiO2 and nanoclay as filler for the basalt reinforced epoxy composite (BE). The impact velocity, filler concentration and temperature are the parameters used for the study. The composites were fabricated using vacuum assisted resin infusion technique (VARI) technique. The fabricated composite specimens were tested by using erosive wear test rig as per ASTM G76 under normal incidence. The result shows that the erosion rate increases with increase in temperature and impact velocity. However, nanoTiO2-filled BE composite exhibits lower erosion rate as compared to Nanoclay filled and unfilled composite. The morphology of eroded surfaces was examined by using scanning electron microscopy (SEM).

Laser Heat Treatment of Cast Irons—Optimization of Process Variables: Part I

1985 ◽  
Vol 107 (3) ◽  
pp. 200-207 ◽  
Author(s):  
A. K. Mathur ◽  
P. A. Molian
Keyword(s):  
Heat Treatment ◽  
Gray Iron ◽  
Case Depth ◽  
Laser Heat Treatment ◽  
Process Variables ◽  
Cast Irons ◽  
Maximum Coverage ◽  
Laser Heat ◽  
Ring Mode ◽  
Better Than

A 1.2 kw CO2-CW laser operating in ring and Gaussian beam modes was used to surface harden gray and ductile cast irons. The microstructure, case depth, hardness, surface integrity, and distortion were studied as functions of process variables (i.e., laser power, focusing optics, beam size, scan rate and thickness of the specimen). The results indicate that the ring mode is preferred over Gaussian whereas ductile iron response to laser heat treatment is better than gray iron. The maximum case depth achieved with minimum melting was 0.38 mm, and the maximum coverage rate obtained was 322.58 mm2/s.

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