Heat-treated Cast Iron Research Articles

The Influence of Load on Dry and Tribocorrosive Sliding of AISI 4330 and 15-5PH against Cast Iron

Environmental conditions, testing variables, and material properties significantly influence the sliding wear behavior of all tribosystems. Such parameters affect the mechanism of wear occurring, govern how the wear scar will be categorized, and control whether transitions occur throughout the test. The present study investigated this through sliding wear tests of AISI 4330, 15-5PH, and heat-treated cast iron in the dry and NaCl regime. Loads of 2, 4, and 6 kg were applied to the cast iron pin in both regimes, with the volume loss results, wear scar morphology, and microstructural evolution analyzed. It was found that the AISI 4330 and 15-5PH discs produced higher volume losses in the dry regime than in the NaCl regime, indicating that the solution had a beneficial effect rather than a detrimental effect versus the dry tribosystem. Beneficial oxidative wear allowed for AISI 4330 to lose less than 15-5PH in the dry regime, with their respective cast iron pins following the same result. Microstructurally, the 15-5PH wear scar cross sections exhibited a mechanically mixed surface layer of refined material mixed with oxides above a layer of grains distorted in the direction of sliding. This highlighted the significant difference between the wear of 15-5PH and AISI 4330, because the latter did not exhibit any areas of interest.

EFFECT OF CARBON CONTENT ON MICROSTRUCTURE EVOLUTION AND PROPERTIES OF HYPEREUTECTIC HIGH CHROMIUM CAST IRON

This study is to reveal the influence of the amount of carbon content on the microstructure evolution, mechanical properties, and wear properties of Hypereutectic High Chromium Cast Iron (HHCCI). The results indicated that the carbon content plays a key role in the regulation of carbides in the cast iron microstructure. As the amount of carbon content rises, the primary carbides in the cast iron microstructure become apparently coarser, and the volume fraction of carbides gradually increases. The carbide volume fraction reaches 62% when the carbon content is 5[Formula: see text]wt.%. When the value of the carbon content increases, the accumulation and growth of eutectic carbides in the heat-treated cast iron become more and more obvious. After heat treatment, a large number of secondary carbides will be precipitated from the austenite matrix, in the form of fine particles or short rods, with a dispersed distribution. The macroscopic hardness of HHCCI has increased. When the carbon content is 3.5[Formula: see text]wt.%, the macroscopic hardness is 61.2 HRC, and when the carbon content becomes 5[Formula: see text]wt.%, it reaches 64.3 HRC. The wear resistance of HHCCI increases with the value of the carbon content increases. When the carbon content was increased from 3.5[Formula: see text]wt.% to 5.0[Formula: see text]wt.%, the wear resistance of the material increased by 85.7%. The wear of HHCCI is mainly adhesive wear and fatigue wear, and the wear morphology is mainly spalling pits and wear debris.

Determination of susceptibility of cast iron with a predetermined chemical composition to shape properties and microstructure through bainitic transformation

.The problem of nanostructuring cast iron is hardly ever reported on scientific reports. Most of the research is undertaken in terms of steel nanostructurization. Bhadeshia states that to obtain a fragmented matrix of steel, the carbon content in the matrix must be at the level of 0.6% C. It should be noted that the carbon in the ferrite-pearlite matrix meets this condition, because the content of this element in the matrix is within the range of 0.7-0.9%. The authors of this work have attempted to evaluate the ability to shape the properties and microstructure of ductile cast iron as a result of not fully completed bainitic transformation, compared to the standard process of obtaining ADI cast iron. The tested material was characterized by a higher degree of alloying elements compared to the basic chemical composition of ADI cast iron. The aim of the work was to maximize the fragmentation of the cast iron microstructure by selecting a low temperature of isothermal transformation, i.e. 40°C above Ms temperature in the lower bainite range. The JMatPro program was used to determine the isothermal transformation temperature. Heat-treated cast iron was subjected to dilatometer tests to compare the results obtained from the computer program, microstructure research and hardness tests. Heat-treated cast iron was subjected to dilatometer tests to compare the results obtained from the computer program, microstructure research and hardness tests.

Tribological Research of Properties of Heat – Treated Cast Irons with Globular Graphite

The contribution deals with the evaluation of tribological properties of materials: isothermally heat-treated cast iron ADI, heat-treated cast iron with globular graphite HTDI with sorbitic structure of the basic metal matrix and heat-treated steel C45. The aim of the research is to gain another knowledge for the application of materials in the condition where the loss of mechanical energy and the loss of material caused by parts wear are being appeared.

VLIV STRUKTURY A PODMÍNEK ZKOUŠKY NA VELIKOST ABRAZIVNÍHO OPOTŘEBENÍ

The paper concerns about the comparison of abrasive wear of testing samples made of various metal materials (steels, isothermally heat-treated cast iron with spheroidal graphite, weld deposit) during both laboratory and operational tests.

Wear on heat-treated cast iron in aqueous abrasive conditions: Vasil'ev, N. A. Russian Engineering Journal (translated from Vestnik Mashinostroeniya) Vol 45, No 8 (1968) pp 79–82

Combination of solid and liquid lubricants to meet emission or environmental requirements of future tribological systems while providing the levels of desired friction and wear performance have received considerable research attention in the near term. The aim of the present work was to investigate the tribological behavior of oil-lubricated (PAO, PFPE, SO, IL and MAC) DLC coated surfaces under the conditions without and with sand-dust particles. The effects of applied load, frequency, and sand-dust particles on the tribological performance of DLC coating were systemically studied. The analysis results showed that solid–liquid lubricating coatings including SO and IL exhibited excellent anti-friction (∼0.026) but relative poor wear-resistance performances under the conditions without and with sand-dust environments. But for PFPE and PAO, they demonstrated the worst tribological behaviors with high friction coefficient and wear rates. The added sand-dust particles lead to the wear rates to the one order of magnitude large than that without sand-dust conditions for all the selected liquid lubricants. The viscosity, contact angle and work of adhesion played an important part in affecting the tribological performances. The lubrication regimes in Stribeck curve for the five kinds of liquid lubricants were affected obviously by the sand-dust particles in different way. The formed transfer films on the coating surface and pin have much influence on the tribological behavior and the transition between lubrication regimes.

Influence of friction conditions on the lattice constant of the ?-phase during the wear of austenitic manganese cast iron

1. Heat treatment influences the crystal lattice and the saturation of the solid solution of the γ-phase of austenitic manganese cast iron. 2. Regardless of the friction and wear conditions (friction without lubrication or with lubrication containing abrasive) the lattice constant of the heat treated cast iron decreases with increasing pressure and the lattice constant changes in the same way. 3. The more saturated the solid solution before the wear resistance tests, the greater the change in the lattice constant.

Cavitation Erosion Resistances of Cast Iron and Chromium Films Plated on Cast Iron under Various Conditions

It is well known that pitting has often occurred on the water side of water cooled diesel cylinder liners. There has been but scanty record of studies made of the interrelations of cavitation erosion, the microstructure of cast iron, the hardness of chromium films plated on cast iron and the hardness of base metals studied.The present study was made with the aim to prevent pitting and to make clear the mechanism of cavitation erosion of cast iron and such chromium films. The magnetostrictive cavitation tests were carried out on specimens that are chromium films with various hardness plated on cast iron, various heat treated cast iron, chromium films with same hardness plated on various heat treated cast iron, carbon steel and chromium films plated on carbon steel.The results obtained are as follows(1) The high cavitation erosion resistance was obtained with plated chromium films of hardness between 850 and 900 Vickers hardness on specimens of chromium films with various hardness plated on cast iron.(2) The cavitation erosion resistance of cast iron increased with increasing hardness of cast iron. It seems that at first the cavitation erosion in the portion with graphite structure was caused by impact stress when cavities collapse, secondly the cracks grew up between graphite and graphite, and finally the destruction occurred.(3) The cavitation erosion resistance increased with increasing hardness of cast iron for specimens of chromium film with 874 Vickers hardness plated on various heat treated cast iron.(4) The high cavitation erosion resistance was obtained on specimens of chromium film plating on carbon steel.

Study on the Wear Resistance of the Isothermally Heat-Treated Cast Iron

Study on the Wear Resistance of the Isothermally Heat-Treated Cast Iron