Cast Iron Alloys Research Articles

Development of optimal formulations of natural alloyed cast irons for metals and engineering, and thermal timing subjected to secondary treatment by the method of resonance-intermittent refining

This article presents the results of the introduction of resonant-pulsed refining technology in production, which made it possible to change the microstructure of blast-furnace irons and significantly increase the operational stability of molds and pallets.

Problems and Perspectives of Implementation of Metalmatrix Composition Materials in Automotive Industry

In this paper we studied possible problems and perspectives of deployment of aluminum-based composite alloys in automotive industry.Aluminum-based composite alloys thanks to their high elastic strength combined with a relatively low mass density, good casting and tribological properties with respect to conventional alloys were implemented in automotive industry over 20 years ago already.These alloys successfully substitute steel, cast iron and titanium alloys in engine, suspension, braking units. However high final cost of auto-components made of strengthened aluminum alloys limits its applications in the industry.In this work we presented the examples of aluminum-based composite alloy technology that reduces the production costs of final product.

High-Temperature Interaction of Molten Gray Cast Iron with Al2O3-ZrO2-SiO2 Ceramic

High-temperature interaction between molten conventional gray cast iron (wt.%: 4.1 C; 1 Si; 0.20 Mn; 0.03 S; 0.04 P, the rest—Fe) and multiphase Al2O3-ZrO2-SiO2 ceramic substrate (wt.%: 51.5 Al2O3, 33.8 ZrO2, 13.3 SiO2, ~ 1 NaO2, 0.15 Fe2O3 + TiO2 + CaO) was examined at a temperature of 1450 °C for 15 min under inert flowing gas atmosphere (Ar, 850-900 hPa) using a sessile drop method coupled with contact heating procedure. Melting, wetting behavior and solidification of gray cast iron sample were continuously recorded with a high-speed high-resolution CCD camera. Under conditions of this study, selected gray cast iron alloy does not wet the Al2O3-ZrO2-SiO2 ceramic forming the final contact angle with average value of θf ~ 135°. The wetting kinetic curve was not smooth and its shape suggests the effect of substrate chemical heterogeneity due to multiphase composition of the substrate material. After the sessile drop test, the solidified drop was easily detached from the ceramic substrate along the drop-side interface showing a lack of bonding between the drop and the substrate. Structural characterization of the drop/substrate couple evidenced the nucleation and growth of graphite at the drop surface and at the drop/substrate interface taken place during solidification and resulting into the formation of discontinuous interfacial graphite layer.

Density and thermal expansion coefficients of liquid and austenite phase in lamellar cast iron

Volume change related defects formation mechanisms are an important detracting phenomenon in production of complex shaped cast components. Among different technical alloys, cast iron behaves in a complex manner due to the combined volume change of the formed phases. The liquid and the austenitic phase are contracting while the graphite phase is expanding during the solidification. The complex volume change in combination with complex casting shapes causes a considerable deviation from isotropy in the solidification domain. The mentioned difficulties are considered the main reason why an extensive research work is condensed in the literature within this topic. The multitude of reported experimental set up and the various efforts to interpret the volume change phenomena in terms of density and thermal expansion coefficients makes the results difficult to compare from different sources. With these difficulties in mind, the present paper presents a broad experimental series and measures unidirectional linear deformation of an industrially spread lamellar cast iron alloy system (Fe-C-2Si) using the push-rod based dilatometer technique. The measurements are divided into two major groups with respect to the liquid iron deformation over the liquidus temperature line, and the austenite deformation below the solidus temperature line. The obtained results are interpreted as thermal expansion coefficients, density variation slopes, and density data at the liquids and solidus temperature. The obtained results are compared with literature data and with calculated values by the Thermo Calc software.

An Overview on Types of White Cast Irons and High Chromium White Cast Irons

Crushing and grinding are widely used in mining, mineral processing, cement making, and coal power generation. The mechanical components that contact with materials being processed are working under the conditions of high abrasion and impact. How to reduce the wearing damages and prevent from the cracking failure of the mechanical parts is one of the crucial challenges facing the operations of many industries, involved crushing and grinding processes. Whit cast irons, and specifically high chromium white cast irons, have been developed and deployed worldwide for making mechanical components of crushing and grinding machines due to the combination of high wear resistance and good mechanical strength. The paper is aimed to give an overview on the white cast iron alloys, and particularly high chromium white cast iron alloys, including their classifications, their standard specifications in USA, China and Australia, their main usages and the new developments.

Problems and Perspectives of Implementation of Metalmatrix Composition Materials in Automotive Industry

In this paper we studied possible problems and perspectives of deployment of aluminum-based composite alloys in automotive industry.Aluminum-based composite alloys thanks to their high elastic strength combined with a relatively low mass density, good casting and tribological properties with respect to conventional alloys were implemented in automotive industry over 20 years ago already.These alloys successfully substitute steel, cast iron and titanium alloys in engine, suspension, braking units. However high final cost of auto-components made of strengthened aluminum alloys limits its applications in the industry.In this work we presented the examples of aluminum-based composite alloy technology that reduces the production costs of final product.

Laser-Induced Plasma as a Method for the Metallic Materials Hardness Estimation: An Alternative Approach

The application of an alternative laser-induced breakdown spectroscopy (LIBS) method based on transversely excited atmospheric (TEA) CO2 laser was investigated for the first time for estimating the hardness of metallic materials. The human eye-safe (TEA) CO2 laser, operating at 10.6 µm, was used for plasma generation. The LIBS spectra were recorded by employing a cost-effective CCD camera for the time-integrated and spatial resolved measurements. The cast iron and aluminum alloys samples with different hardness have been tested. The ratio between the magnesium ionic and neutral lines in LIBS spectra was applied for estimating the material hardness. In addition, the hardness of all samples included in this study was determined using the conventional method for material hardness determination, i.e. Vickers hardness test. The linear dependence of magnesium lines intensity ratio on the sample’s hardness was obtained for both kinds of materials. Profilometric measurements were used to verify that the newly-introduced method is almost nondestructive for the investigated metals. The results obtained in the present work confirmed the potential of using this original LIBS system not only for the fast elemental analysis but also for the direct estimation of the hardness of metals and alloys.

Design and Analysis of Single Plate Clutch by Mathematical Modelling and Simulation

This paper addresses Modeling and analysis of single plate clutch which is used in Tata Sumo vehicle. Clutch is the most significant component located between engine and gear box in automobiles. The static and dynamic analysis were developed for a clutch plate by using finite element analysis (FEA). The 3D solid model was done using CATIA V5R16 version and imported to ANSYS work bench 19.0 for structural, thermal and modal analysis. The mathematical modelling was also done using six different materials (i.e. Steel, Stainless Steel, Ceramics, Kevlar, Aluminum alloy and Gray Cast iron); then, by observing the results, comparison was carryout for materials to validate better lining material for single plate clutches using ANSYS workbench 19.0 and finally conclusion was made.

Application of Alloyed Cast Iron to Increase the Durability of Products of the Mining and Metallurgical Industry

The article shows the relevance of the use of alloyed cast iron in mining and metallurgical engineering. The use of cast iron alloyed with titanium and vanadium has not been sufficiently studied for the working bodies and friction units of mining machines, such as pumps, coal scoops, hydrocyclones, crushers and mills. They have the main abrasive type of wear. This work considers the influence of titanium and vanadium on the mechanical properties. The performance indicators of parts of mining machines and metallurgical products in contact with high-abrasive and high-temperature environments is also considered. The optimal content of titanium and vanadium in gray cast iron in the range of 0.05-0.1% is set. This provides the required strength properties of the components, while increasing their heat resistance. Bushings made of this cast iron have the required wear resistance and can improve the operational reliability of equipment in mining and metallurgical industries.

Important features of casting systems when casting alloy cast irons in sand-clay molds

Important features of casting systems when casting alloy cast irons in sand-clay molds

Influence of S and Mn on mechanical properties and microstructure of grey cast iron: An overview

In the present review article, influence of S and Mn on microstructure and mechanical properties is studied. Additionally, effect of manganese and sulfur on the wear property of grey cast iron was also reviewed. The data from different experiments were taken under consideration and studied for the examination of the alloyed cast iron. The study describes that on increasing the manganese content of the grey cast iron, wear coefficient and hardness decreases and impact energy increases. The main motive of addition of manganese is to control the adverse effect of sulfur on the mechanical properties of grey cast iron. Moreover, the presence of manganese counter the formation of FeS, which is the reason for hot shortness in the alloy.

Effect of niobium addition on the properties and microstructure of a high chromium cast iron alloy

High chromium cast iron (HCCI) is usually employed in equipment that experience high abrasive wear and therefore requires high resistance. Niobium could be added to these alloys to improve their resistance to wear. This study consisted in addressing the influence of 0.5% and 1.0% of niobium on the microstructure of a 26% Cr and 2.8% C HCCI alloy. Standard samples – without niobium – and samples with 0.5% and 1.0% Nb were melted, cut and then machined into adequate dimensions for tests. Two groups of samples – with and without heat treatment – were analyzed through X-ray Diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), Vickers and Rockwell-C hardness. Carbides Volume Fraction (CVF) was quantified in the heat-treated samples. The majority of NbC carbides were observed to be thin and presented a hook shaped morphology. In addition, it was noted a precipitation of Nb-rich layers around the M7C3 carbides, which could act as a higher hardness coating. There was significant reduction in carbide volume fraction, from an initial 33.3% to 28.1% for the 0.5 % Nb alloy, and further reduction to 24.9% for the 1.0% Nb alloy, it was also noted an alteration on the quasi-eutectic microstructure to a hypoeutectic microstructure. The NbC carbides prevented hardness reduction as a result of lowering the CVF in heat-treated alloys; however, the alloys without heat treatment experienced reductions in hardness. Keywords: Heat treatment, niobium, high chromium cast iron, microstructure. 1

Weight Reduction and Structural Validation of Four Wheeler Disc Brake with Various Materials

Safety side in engineering has been thought of as variety one priority in development of latest vehicle. Each single system has been studied and developed so as to satisfy safety demand. Instead of having bags, sensible suspension systems, sensible handling and safe cornering, there’s one of most crucial system within the vehicle that is brake systems. Without brake within the vehicle can place a traveller in unsafe position. Therefore, it’s a requirement for all vehicles to own correct brake. Due to vital system within the vehicle, several of researchers have conducted a study on brake and its entire part. In this project, the author has conducted a study on aerated and traditional disk brake of traditional traveller vehicle with full load of capability. The brake must be sufficiently designed in order to dissipate the heat generated from the braking process adequately for safe braking system performance. The aim of our project is to design and investigate the braking performance of the low cost passenger car with various materials like stainless steel, cast iron and aluminium alloy. The disc brake structure is changed with cross-drilled holes on the rotor of the disc for more heat dissipation using CATIA V5 R21 and performance study in term of its Structural property was determined using ANSYS finite element analysis software.

Influence of Cryogenic Temperatures on Mechanical Properties of Valve Seats of Internal Combustion Engines

Valve seats of internal combustion engines are used in cylinder heads, due to increase the strength and abrasion resistance of the intake and exhaust valve seats. Valve seats are made from alloy cast iron, high-alloy steels, wear-resistant alloys and seats made using powder metallurgy. The valve seats are pressed into the head. Some materials must be deep-frozen before pressing to reduce the pressing overlap. The overlap is large, in the order of tenths of a millimetre, due to the guaranteed seating of the seat in the cylinder head. The amount of overlap depends also on the material of the cylinder head. Liquid nitrogen (about -196 °C) is used for freezing. In our case, these are monometallic seats, made by technology of precision casting from cobalt alloys. A particular type of cobalt alloy uses the trade name STELLITE.

The effect of niobium addition on the microstructure and properties of cast iron used in cylinder head

Cylinder head is one of the most important parts of heated components in the engine, while cracking due to low strength and large residual stress at high temperature is the main failure mode of cylinder head. With the growing demand of good performance and high reliability, gray cast iron with trace alloying element and optimized annealing process are probably effective ways in obtaining suitable materials. The effect of niobium addition on the microstructure and properties of cast iron used in cylinder head is studied in this paper. The results show that, the tensile strength, toughness, fatigue properties and thermal fatigue properties of gray cast iron are improved by adding trace niobium elements. The specimen with 0.20% niobium shows better comprehensive mechanical properties than others. The addition of trace niobium elements can not only refine the graphite, eutectic cell, carbide and phosphorus eutectic, but also reduce the pearlite lamellar space, thus strengthening the matrix. The cylinder head is made by cast iron with 0.20% niobium addition, and the annealing process of thermal aging is optimized. The residual stress of cylinder head can be maintained at a low level by adopting annealing process with higher holding temperature, longer holding time, lower cooling rate and lower outlet temperature. The analysis of microstructure, mechanical properties and residual stress for niobium alloyed cast iron is helpful for solving the cracking problem of cylinder head, and providing scientific basis for improving engine reliability.

Corrosion fatigue of austenitic cast iron Ni-Resist D5S and austenitic cast steel HK30 in argon and synthetic diesel exhaust at 800 °C

To increase the understanding of the corrosion-fatigue mechanisms in two cast iron-alloys used in exhaust manifolds, low-cycle fatigue tests at 800 °C in argon and synthetic diesel exhaust as well as isothermal oxidation tests in the exhaust atmosphere are conducted. The corrosion impacts on the fatigue life of the materials are quantitatively evaluated from comparing the ∊-N curves, and examined from characterization through SEM, EDX, EBSD and EPMA. The materials show very different behaviors to the synergistic effect of corrosion and fatigue. Different theories have been suggested based on the findings.

3D phase-field computations of microsegregation in nodular cast iron compared to experimental data and Calphad-based Scheil-prediction

The redistribution of solute elements during processing of a nodular cast iron alloy was simulated for the first time comprehensively over time and 3D space. Numerical predictions had so far been limited to 1D models, neglecting local morphological aspects and commonly also diffusion and growth in solid-state. Application of the standard multi-phase-field method was hindered by the inherent simplifying assumption of equal and constant molar volume, causing artificial piling-up of solute and biased kinetics during modelling of graphite growth. A recently developed volumetric multi-phase-field approach now accounts for the changing partial molar volume of the individual elements. The Calphad-based phase-field study was benchmarked to experimental cooling and nodule density data, and the predicted as-cast distributions were validated by experimental segregation analysis. The combined numerical and experimental findings were furthermore used as a basis to discuss simplifying assumptions commonly made in 1D Scheil-type models.

Intermetallic Phases in Alloyed Cast Iron with 18%Si Addition

Intermetallic Phases in Alloyed Cast Iron with 18%Si Addition

Corrosion behavior of newly developed heat treated 10Mn-2Ni-3.5Cr-1.5Cu alloy

A new cast iron alloy of 10Mn-2Ni-3.5Cr-1.5Cu is developed through casting route. The experiments are carried out to investigate the effect of heat treatment on microstructure, hardness and corrosion behavior of the newly developed 10Mn-2Ni-3.5Cr-1.5Cu alloy. Alloy 10Mn-2Ni-3.5Cr-1.5Cu is subjected to heat treated at 800 to 950 °C for 1, 3, 5 and 7 h, and cooled in the air at room temperature. The microstructure of the alloy is characterized by optical and scanning electron microscopy at various experimental stages. The microstructure consists of spherical and finer carbides with the austenite matrix. The different phases are investigated by XRD and EDS. Several carbides such as M3C, M5C2 and M7C3 are observed, which are formed with an austenitic matrix. However, the increase in heat treatment temperature/time leads to an increase in the volume fraction of austenite and dissolution of carbides in the matrix. Corrosion study is carried out in the solution of 5% NaCl using the weight loss method for 7 and 30 days. The corrosion rate and hardness are observed to be lower after heat treatment at 900 and 950 °C for 7 h due to the dissolution of carbides. The results show that this alloy has corrosion resistance equivalent to the high-cost Ni-based alloys. Therefore, the present research aims to develop a new low cost cast iron alloy with high corrosion resistance.

Microstructure, abrasive wear and corrosion characterisation of laser metal deposited Fe-30Cr-6Mo-10Ni-2.2C alloy

Advances in Laser Metal Deposition (LMD) provide technical opportunities such as the geometric restoration of worn components and custom surface coatings to enhance wear and corrosion resistance. Commercial applications include high Cr white cast iron (HCWCI) alloys for mining applications. In this study, a Fe-2.2C-30Cr-10Ni-6Mo alloy was deposited on mild steel substrates to characterise the effect of the LMD process, and a subsequent 1030 °C/4 h s heat treatment, on the microstructure, corrosion behaviour, and abrasive wear behaviour. The LMD microstructure consisted of fine eutectic Cr enriched M7C3 and Mo enriched M2C carbides in a γ-Fe matrix. This led to good abrasive wear and corrosion properties. The post heat treatment had an adverse effect on both the abrasion and corrosion resistance of this alloy, primarily due to the transformation of M7C3 to softer M23C6 carbides, and Cr depletion in the matrix.