High Chromium Cast Iron Research Articles

The Erosion–Corrosion Behavior of Eutectic High Chromium Cast Irons Reinforced by TiC Particles

In this work, high chromium cast irons (HCCIs) reinforced by TiC particles are designed and fabricated to improve the erosion–corrosion and wear resistances of materials for the pumping and handling applications. The TiC particles are formed by the in situ solidification method. The experimental results show that the hardness of as-cast HCCIs is improved significantly with TiC volume fraction. It can be as high as 63 HRC when the TiC volume fraction is 9.8%. The introduction of TiC increases the abrasive wear resistance of the HCCIs in both as-cast and heat-treated states. However, it is unexpected to find that the presence of TiC significantly reduces the erosion–corrosion performance. It suggests that corrosion-enhanced erosion is the dominant mechanism that controls the mass loss of the TiC-strengthened HCCIs.

Assessment of the Impact of Wear of the Working Surface of Rolls on the Reduction of Energy and Environmental Demand for the Production of Flat Products: Methodological Approach.

An important element in the correct operation of the rolling mill is appropriate planning of the condition of the rolls because this factor constitutes a limiting element in the production process. In this work, with the aim of indicating the method of proper use of production tools–metallurgical rollers during their operation in a Polish rolling mill, the wear and tear of particular kinds of rollers built in the whole rolling set was determined. For this purpose, data were collected at the strip mill from grinding processes, production reports and roll files, while our statistical analysis, laboratory calculations and measurements were used. These data were used to perform computer calculations on the service life of metallurgical rollers installed in the rolling line. Wear mechanisms were identified in industrial practice. The characteristic features of roller wear were investigated using non-destructive tests, including eddy currents. The laboratory tests reproduced the wear mechanisms in very hot rolling rolls. The statistical method for determining the service life of working rolls indicated that their reconstruction is determined both by natural physical phenomena and inappropriate use in about 30% of cases, mainly in the F5 and F6 cages of the finishing unit. Calculations indicated the possibility of replacing the working rolls made of high chromium cast iron Hi-Cr with those made of HSS in the F5 and F6 cages, which will contribute to an increase in the durability of the rolls, a reduction in production costs and a decrease in the number of roll rebuildings. The service life of HSS rolls is 14,000–20,000 Mg of rolled material per 1 mm of wear on its surface in the radial direction, compared to 2000 Mg for rolls made of high chromium cast iron Hi-Cr. The constructed model may be a source of information for further analyses and decision-making processes supporting the management of metallurgical enterprises. On the basis of the constructed model, it was shown that the analyzed projects, depending on their type and technical specification, will bring measurable economic benefits in the form of reduced annual energy consumption and environmental benefits in the form of reduced carbon dioxide emissions into the atmosphere. The constructed model of the roll consumption, verified in the real conditions of the rolling mills, will contribute to the fulfillment of energy and emission obligations with the EU.

High chrome cast iron for mineral processing and conveying equipment parts

The main reasons for the formation of microand macrocracks and other defects in waterjet castings, which significantly reduce their service life, are analyzed. It has been established that the introduction of ferroalloys together with the charge to the bottom of the arc furnace bath leads to a significant segregation of elements along the height (volume) of the melt in the bath furnace, and large primary chromium carbides remain in the casting structure. They, as a rule, form eutectics with austenite in the form of large conglomerates, which contribute to the appearance of microcracks in castings during their mechanical and thermal processing. It is shown that alloying, modification and homogenizing exposure of the melt for 5 min at 1550 °C and subsequent refining have a significant effect on the structure and morphology of the carbide phase and structural components of the metal base of high-chromium cast iron and purify it from harmful impurities and non-metallic inclusions. In addition, the amount of primary carbides is reduced, the formation of austenitic-carbide eutectic conglomerates is excluded, and the dispersion of the carbide phase and the structure of high-chromium cast iron are increased. Based on the ICH300Kh28NMWFTP cast iron created by JSC «NPO «TSNIITMASH», an effective export technology for the manufacture of waterjet castings has been developed, which makes it possible

Study on microstructure and abrasive wear properties of in-situ TiC reinforced high chromium cast iron matrix composite

In this paper, the TiC particle-reinforced high chromium cast iron matrix composite was prepared in situ by the method of injection infiltration, and the effect of adding different volume fractions of moderators on the size of the reinforcing particles, the volume fraction of the reinforcing particles and the abrasive wear of the composite was systematically studied. Performance impact. The research results show that the TiC particles obtained by the in situ method are uniformly distributed in the matrix of high chromium cast iron, and the interface between the particles and the matrix is clean. And as the volume fraction of the moderator increases, the size of the obtained TiC particles becomes smaller and more uniform, and the volume fraction of the reinforcing particles also gradually decreases with the increase of the volume fraction of the moderator. And the introduction of TiC has increased the hardness of the material by up to 69.036%. Abrasive wear experiments show that the introduction of the moderator makes the reinforcing particles smaller, which further improves the wear resistance of the composite material, and the composite material with 20% moderator content has the best wear resistance, compared to The wear resistance of the metal matrix material is increased by 1.8 times.

Microstructure evolution and mechanical properties of high-boron steel with different ratios of boron and carbon

Boron and carbon contents are the main factors influencing the properties of high-boron steel. In this study, experimental samples with different boron-to-carbon ratios (%B/%C) were prepared. The microstructures of the different samples were observed, and their hardness, bending strength, and impact toughness were investigated. Results show that the main microstructures in the investigated high-boron steel samples are the eutectic Fe2B structure with a fishbone shape and the ternary peritectic Fe3(C, B) structure with a chrysanthemum shape. When the boron content is 2.5wt.% and the carbon content is 0.43wt.% (i.e., %B/%C=5.82), the overall mechanical properties of the alloy are the best. The alloy’s hardness, bending strength and impact toughness reach their maximums, which are 67.3 HRC, 1,267.36 MPa and 6.19 J·cm-2, respectively. The optimized alloy is compared with conventional materials exhibiting excellent wear resistance (namely, high-manganese steel and high-chromium cast iron) through two-body and three-body abrasion tests. The wear resistance of this high-boron steelinvestigated in this work is found to be superior to those of the more common materials.

RETRACTED ARTICLE: Machinability study on dry machining of white cast iron by polycrystalline cubic boron nitride inserts

We, the Editors and Publisher of Machining Science and Technology have retracted the following article: Xin Guo, Ling Chen, Wu Zhao, Hao Wan, Huiting Wen & Jinming Zhou (2022) Machinability study on dry machining of white cast iron by polycrystalline cubic boron nitride inserts, Machining Science and Technology, 26:2, 137–159. https://doi.org/10.1080/10910344.2022.2044851 Following publication, the authors requested the withdrawal of this article in 2022 due to conflicting findings with their recent research studies. However, upon further investigation by the Publisher, in collaboration with the Editors, it was found that this article has significant similarities with the following published article which has not been acknowledged appropriately: Ling Chen, Jan-Eric Stahl, Wu Zhao, Jinming Zhou. (2018). Assessment on abrasiveness of high chromium cast iron material on the wear performance of PCBN cutting tools in dry machining, Journal of Materials Processing Technology 255, 110–120. https://doi.org/10.1016/j.jmatprotec.2017.11.054. These unacknowledged similarities are in the form of: text overlaps in the sections “Material preparation”, “Nanoindentation test”, and “Tool wear”, and; reused images included in figures 5 and 6, which are not referenced. Upon query, the corresponding author has not been able to provide a satisfactory explanation for the significant level of overlap. As this is a serious breach of the journal’s editorial policies, we are retracting the article from the journal. The authors disagree with the Publisher’s and Editors’ reasons for retraction. We have been informed in our decision-making by our editorial policies and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

Microstructure and Sliding Wear Behavior of High Chromium Cast Iron Strengthened Low Carbon Steel Composite

Microstructure and Sliding Wear Behavior of High Chromium Cast Iron Strengthened Low Carbon Steel Composite

Determining the Residual Stresses in High-Chromium Cast Iron Plasma Coatings

The paper presents the results of studies of the plasma spraying modes effect on the level of residual stresses in coatings. The analysis of experimental data has shown that the sign of residual stresses is not changed in the spraying process. The magnitude of the tensile stresses mainly depends on the temperature of samples heating, the biggest influence being that of plasma torch current arc. An increase in the current leads to an increase in the substrate temperature, which is explained by the increase in the thermal power of the plasma jet. An increase in the flow rate of the plasma-forming gas leads to a decrease in the temperature of the samples, since the heat content of the plasma decreases. An increase in the spraying distance has a similar effect, and its increase leads to a decrease in the substrate temperature. We obtained the functional dependence of the residual stress level on the plasma spraying modes.

Microstructure and properties of modified as‐cast hypereutectic high chromium cast iron

AbstractThe present work studied the effects of different modification treatments on the microstructure and mechanical properties of hypereutectic high chromium cast iron containing about 35 wt% chromium and 4.0 wt% carbon. It was found that the primary carbides in the hypereutectic high chromium cast iron were all refined to different levels after different modification treatments. Among them, the best result was obtained by adding 0.6 wt % rare earth magnesium, and its average carbide diameters was 43 μm, which is almost half of the unmodified specimen. After modification, the mechanical properties have been improved, and the refinement of primary carbides can greatly improve its impact toughness. The impact toughness of the specimen modified by adding 0.6 wt % rare earth magnesium was the largest, reaching 7.0 J cm−2, and the impact toughness of un‐modification specimen was the worst, only 4.5 J cm−2. The refining of primary carbides does not have much effect on the hardness. The hardness of the sample with 0.6 wt % rare earth magnesium and 0.3 wt % TiBAl is the highest, and its value is 58.0 HRC. The wear resistance increases with the refinement of primary carbides.

Effect of heat treatment on microstructure and properties of modified hypereutectic high chromium cast iron

Abstract The effect of heat treatment on the microstructure, hardness and wear resistance of modified hypereutectic high chromium cast iron (HCCI) was investigated. The results show that the quenching treatment partially dissolves the edges of the primary carbides, and the sharp corners become rounded and blunt. As the quenching temperature increases, the carbide re-dissolves into the matrix, and the hardness and wear resistance first increase and then decrease. The hardness and wear resistance are the best when quenched at 1000 °C. After tempering, the martensite is transformed into tempered martensite, and the precipitation of secondary carbides increases. As the tempering temperature increases, the secondary carbides gradually become coarser. When the tempering temperature is 500 °C, the hypereutectic HCCI shows the highest hardness and the best wear resistance. When tempered at 400 °C, hypereutectic HCCI shows the best erosion and wear resistance.

Effect of B4C on bending strength of ZTA ceramic reinforced high chromium cast iron matrix composites

ABSTRACT Zirconium dioxide-toughened aluminum oxide (ZTA) ceramic-reinforced high chromium cast iron (HCCI) matrix composites were prepared by vacuum pressure-free infiltration, and the effects of active additive boron carbide (B4C) (10%, 12%) on the interface binding ability was studied systematically. Results showed the wettability between HCCI and ZTA could be improved after the addition of B4C, which could result in a metallurgical combination by forming a transition layer. When the content of B4C additive was 10%, the Brinell hardness of ZTA/HCCI composites reached 645 N/mm2 in the as-infiltration state, and the bending strength was more than twice of HCCI. After heat treatment, the hardness and bending strength increased significantly, which reached 676.1 N/mm2 and more than three times of HCCI, respectively.

Multi-objective optimization of alloying elements to enhance the wear resistance and impact strength of HCCI produced by furan sand mold

High Chromium White Cast Iron (HCWCI) plays a major role in manufacturing of wear-resistant components. Due to unique wear resistance property, attribution to the additions of carbide forming elements, they have been used for mill liner applications. By varying the wt% of alloying elements such as Cr, Ti, and Mo, the wear resistance and impact strength of High Chromium Cast Iron (HCCI) can be increased. To enhance the wear resistance property according to Central Composite Design (CCD), 16 samples were fabricated by varying the wt% of alloying elements. To fabricate the samples, furan sand molds were prepared and used for the further casting process. The properties of Furan sand mold enhance the mechanical properties and reduce the mold rejection rate, production time, etc. To attain the optimum Wear Rate (WR) and Impact Strength (IS) value without dominance, optimization techniques such as Response Surface Methodological (RSM) and Particle swarm optimization (PSO) are employed to solve the multi-objective problem. The RSM and PSO predicted optimum solutions are compared by using the Weighted Aggregated Sum Product Assessment (WASPAS) ranking method. The WASPAS result revealed that when compared to the RSM result, the PSO predicted optimal wt% of chemical composition (22 wt % Cr, 3 wt % Ti, and 2.99 wt % Mo) gives the optimum WR value (53 mm3/min) and IS value (3.77 J). To validate the PSO result, experiments were carried out for the predicted wt% of alloying elements and tested. The difference between the PSO predicted result and experimental result is less than 5% error which clearly shows that PSO is an effective method to solve the multi-objective problem.

Microstructure and tensile behavior of high-chromium cast iron/low-carbon steel composite fabricated by accumulative roll-bonding

In the present study, a composite material of high chromium cast iron (HCCI) dispersed in low carbon steel (LCS) matrix was fabricated by the technology of accumulative roll-bonding (ARB). The microstructure characteristics were investigated using scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). The tensile behavior and fracture characteristics of the composite were analyzed. The obtained microstructures illustrated that the HCCI was dispersed in the LCS after 3rd ARB cycle, forming a kind of composite material somewhat similar in its structure to a concrete. The coarse Cr-carbides of HCCI were broken and refined obviously through the hot-rolling deformation. However, some microcracks were formed on the fractured Cr-carbides of HCCI. The two materials were bonded by mechanical and metallurgical bonding, and a diffusion band with a thickness of ∼10 µm was formed on the interface. Compared with the as-cast HCCI plate, the composite material after 3rd ARB cycle possessed good comprehensive tensile properties. The fracture characteristics of the composite material included the multiple tunnel fracture of HCCI and the shear fracture of LCS.

Influence of Niobium Adding on the Microstructure and Abrasive Wear Resistance of a Heat-Treated High-Chromium Near-Eutectic Cast Iron Alloy

High chromium cast iron (HCCI) with levels around 26% Cr - 2.9% C according to ASTM A 532 IIIA is widely used in systems where high abrasive wear resistance is required. To evaluate the niobium influence, HCCI with 0.5% Nb and 1% Nb additions were melted, besides one without niobium addition of for comparison. For characterization, X-ray diffractometry, scanning electron microscopy (SEM), Vickers microhardness tests, Rockwell C hardness, carbide quantifications, quantification of the retained austenite by Mössbauer spectroscopy, and rubber wheel abrasion test according to procedure A of ASTM G-65 were performed. The results indicated a reduction in the average size, average perimeter, and carbides volumetric fraction (CVF) due to the addition of niobium, also changing the microstructure of the HCCI from eutectic to hypoeutectic. In some regions, NbC0.75 carbides formed a coating around M7C3 carbides. The 0.5% Nb alloy showed the best performance in the rubber wheel abrasive wear test, with a 37% average volume loss reduction as compared to the sample without niobium addition with a 130N load and 34% with a 45N load. The 0.5% Nb alloy also had the highest content of retained austenite among the investigated alloys.

Influence of silicon and aluminum content on defectiveness of high-chromium cast iron hardfacing layer of bimetallic sheet

The process of arc surfacing of the wear-resistant layer of metal, which corresponds in composition to high-chromium cast iron, on low-carbon steel substrate was studied. Spectral analysis of the metal chemical composition and metallographic studies of the obtained structures were used. Based on the statistical processing of experimental data, the dependences of the hardness of the applied white cast iron layer, the presence of cracks and pores in it on the chemical composition of the applied metal were obtained. The novelty of the conclusions is in the specific recommendations for limiting the content of silicon and aluminum in the surfacing materials. The results of research can be used for the reduction of the level of defectiveness of bimetallic layers that are subjected to various types of abrasive wear and are made with the use of electric arc technology.

Effect of Carbon Addition on the Passive Behaviour of Hypoeutectic High Chromium Cast Irons

Effect of Carbon Addition on the Passive Behaviour of Hypoeutectic High Chromium Cast Irons

Effect of solutes on the formation of primary carbides during solidification of hypereutectic high chromium cast irons through thermodynamic modeling

Effect of solutes on the formation of primary carbides during solidification of hypereutectic high chromium cast irons through thermodynamic modeling

Specific Features of the Fracture of High-Chromium Cast Irons Under Abrasive Wear

Specific Features of the Fracture of High-Chromium Cast Irons Under Abrasive Wear

The Effect of Vanadium Content Coupling with Heat Treatment Process on the Properties of Low-Vanadium Wear-Resistant Alloy.

The development of wear-resistant materials with excellent properties is of great research value in the manufacturing industry. In this paper, a new kind of low-vanadium wear-resistant alloy was designed and characterized to unveil the influence of vanadium content coupling with heat treatment on the microstructure, hardness, and abrasive wear property. The performances of commercial high chromium cast iron (HCCI) and the new low-vanadium wear-resistant alloy are compared. The alloy with 3 wt.% vanadium quenched at 900 °C and tempered at 250 °C, possessing VC, Mo2C, and M7C3 distributed in the martensite matrix, displayed a wear resistance two times better than the HCCI. The results showed that the increase of vanadium content from 0.98 wt.% to 3.00 wt.% resulted in a decrease in the size of M7C3 and a more homogeneous distribution of M7C3. VC with a bimodal distribution is effective for impeding grooving or indenting by abrasives because of their high hardness, which plays a vital role in improving the wear resistance of low-vanadium wear-resistant alloy.

Compression Performance and Abrasive Wear Resistance of CuNi‐Modified Zirconium Oxide‐Toughened Alumina Particles‐Reinforced Iron Matrix Composites

Compact and continuous Ni‐coated zirconium oxide‐toughened alumina (ZTA) particles (ZTAp@Ni) and CuNi‐coated ZTA particles (ZTAp@CuNi) are prepared by electroless deposition. The thicknesses of the Ni and CuNi coatings are 6.84 and 21.35−43.10 μm, respectively. The ZTAp@Ni‐ and ZTAp@CuNi‐reinforced high‐chromium cast iron (HCCI) composites are fabricated by nonpressure cast‐infiltration method. Results show that compact interfacial bonding is formed in S3′‐ZTAp@CuNi/HCCI without any casting defect. The addition of Ni element can effectively improve the amount of (Cr,Fe)7C3 and refine the grains in HCCI matrix, and Cu element can improve the strength and toughness of the matrix. The compression performance testing shows that the compressive strength and yield strength of S3′‐ZTAp@CuNi/HCCI are up to 1128.03 and 1049.40 MPa, respectively. In addition, three‐body abrasive testing demonstrates that the abrasive wear resistance of the S3′‐ZTAp@CuNi/HCCI is optimal. This can be attributed to the compact combination between ZTAp@CuNi and HCCI matrix, which benefits the load transfer and the protection of ZTA particles to avoid brittle fracture and debonding. So, the appropriate additions of Cu and Ni elements, that is, the thickness and content control of CuNi coatings on ZTA surfaces, are very crucial for the performance improvement of composites.