The application of large-size plastic injection molds is continuously increasing in automotive and aerospace industries. Having uniform hardenability over the entire volume of the large forged steel blocks is an important scientific and technological challenge. In the present paper, the influences of chemical composition and cooling rate on the kinetics of phase transformations in three medium carbon low alloy forged steels were investigated. A combination of high-resolution dilatometry, light and electron microscopy, X-ray diffraction analysis, electron backscattered diffraction mapping, and microhardness measurements were employed to accurately determine the critical transformation temperature, identify microstructural constituents (martensite, bainite, pearlite, ferrite, and retained austenite), and quantify the percentages of retained austenite for each experimental condition. Using seven different cooling rates (from 0.003 to 3 °C s−1), the continuous cooling transformation diagrams were constructed for the three investigated steels. The influences of composition and cooling rate on transformation kinetics were analyzed and quantified using the carbon equivalent (CE) notion. The obtained results showed the early formation of bainite at a cooling rate of 0.01 °C s−1 for the steel with higher value of CE. Similarly, it was found that the incubation time for ferrite and pearlite formation is influenced by the CE value, while for some cooling rates martensitic transformation occurred regardless of CE values.

Characteristics of Austenite Transformation During Post Forge Cooling of Large-Size High Strength Steel Ingots

In engineering applications, to increase productivity and to decrease production costs, the selection of the proper engineering material is essential. At that point, machining operations directly affect the production costs. Therefore, determination of the material with the desired mechanical properties and easy-to-cut characteristics has a critical importance. This situation is currently gaining more importance in especially defense industry applications in which high strength engineering materials are heavily employed. In addition, tool performance and final product quality are directly influenced by the cooling and/or lubrication conditions in particularly interrupted cutting operations. In this study, machinability characteristics of G18NiMoCr3-6+QT1 cast steel (CS) and 1050-6 austempered ductile iron (ADI) with similar mechanical properties during milling operations were investigated. The tests were performed using TiAlN coated cemented carbide (WC-Co) end mills under dry, conventional cutting fluid (CCF), and minimum quantity lubrication (MQL) conditions. Under each condition, the variations of cutting forces, tool wear, average surface roughness (Ra), and subsurface microstructure and microhardness were analyzed for both materials and then compared to one another. Test results showed that 1050-6 ADI led to further tool wear in comparison to G18NiMoCr3-6+QT1 CS. According to obtained results, dry condition is more favorable than CCF and MQL conditions in terms of cutting forces, surface roughness, and tool wear for both types of material. In addition, examinations on subsurface microstructures showed that MQL conditions provided an effective cutting environment to maintain microstructural stability of workpiece materials.

Machinability evaluations of austempered ductile iron and cast steel with similar mechanical properties under eco-friendly milling conditions

The wear resistances of austempered ductile iron (ADI) were improved through introduction of a new phase (carbide) into the matrix by addition of chromium. In the present investigation, low-carbon-equivalent ductile iron (LCEDI) (CE = 3.06%, and CE represents carbon- equivalent) with 2.42% chromium was selected. LCEDI was austenitized at two different temperatures (900 and 975°C) and soaked for 1 h and then quenched in a salt bath at 325°C for 0 to 10 h. Samples were analyzed using optical microscopy and X-ray diffraction. Wear tests were carried out on a pin-on-disk-type machine. The effect of austenization temperature on the wear resistance, impact strength, and the microstructure was evaluated. A structure–property correlation based on the observations is established.

Effect of austenitization temperature on microstructure and mechanical properties of low-carbon-equivalent carbidic austempered ductile iron

The impact of cutting speed and depth of cut on cutting force during turning of austempered ductile iron

In this paper, we investigated the effect of titanium modification on microstructures and properties of carbidic austempered ductile iron (CADI) containing 3.72 wt.% C, 2.77 wt.% Si, and 0.51 wt.% Mn. The results showed that with the addition of 0.1 wt.% Ti, TiC particles were formed, and distributed in carbides and matrix. Microstructural observation indicated that the maximum diameter of graphite nodules decreased from 58 to 40 μm, and the shape of carbides transformed from network to fragmentation, which was related to the nucleation of the eutectic structure (γ + (Fe, Cr)3C) where TiC particles act as the nucleus. After isothermal quenching at 300 °C, the hardness of Ti-bearing CADI was 3.5 HRC higher than ordinary CADI, and the impact toughness was increased by 14.3%. Additionally, due to the decrease in exfoliation, the wear loss of Ti-bearing CADI was 14.8% lower than ordinary CADI during the block-on-ring wear test at the surface load of 300 N.

Effect of Ti Modification on Microstructures and Properties of Carbidic Austempered Ductile Iron

Austempered Ductile Iron (ADI) is a relatively novel material to the industrial market and it is often reported that ADI is a difficult material for machining. This work mainly focuses on machinability studies of ADI. The Ductile Iron (DI) was austempered at 250 °C for different durations and the process window for austempering was established by studying the microstructure. The microstructural characterization of the material was done using optical microscopy, SEM and XRD. The samples austempered as per the process window were then subjected to turning using a TiAlN-coated tungsten carbide insert to study the effect of cutting parameters, namely the cutting speed & the depth of cut. The effect was investigated in terms of the surface roughness obtained. It has been observed that increasing cutting speed results in decreasing of surface roughness and improvement in surface quality. The surface quality deteriorates with decreasing the cutting speed. Based on the observations it is concluded that when ADI is subjected to turning with TiAlN-coated tungsten carbide insert, the combination of a depth of cut of 2 mm and feed rate of 0.1 mm/rev results in the best surface quality when the cutting speeds in the range 150–200 m/min are employed. The observed machinability behaviour was investigated in light of the microstructure of the material obtained under the given austempering conditions and a structure–property co-relation was established between the two. High-speed cutting with deeper depth of cut not only reduce machining expenses by increasing production volume and rate, but also results in good surface quality of machined parts.

The Effect of Cutting Speed and Depth of Cut on Surface Roughness During Machining of Austempered Ductile Iron

Chromium bearing Austempered Ductile Iron (ADI) has been recently in the news for its improved wear performance over the ADI. The work presented below was taken up to study the effect of different austenitisation temperatures on the microstructu wear performance of the Carbidic Austempered Ductile Iron (CADI). In this investigation Cr bearing ductile iron was subjected to austempering treatment to obtain an ausferritic microstructure. Two different austenitisation temperatures were selected whereas, the austempering temperature and time was kept unchanged. Microstructure and wear performance of this alloy, austenitized at two different temperatures was studied. Keywords—Austempered Ductile Iron, Carbidic Austempered Ductile Iron.Austenitization temperature.

Effect of Austenitization Temperature on Wear Behavior of Carbidic Austempered Ductile Iron (CADI)

The present paper examines and compares the influence of austempering parameters such as temperature and time on the isothermal transformation and microstructural changes of ductile iron. To identify the compositional and structural changes during an isothermal transformation, a very wide austempering period is chosen at a transformation temperature for the precise determination of the process window. XRD, optical, and scanning electron microscopic techniques are exploited to identify and analyze the changes in the austempered structure, at austempering temperatures of 250°C and 400°C. The various structural parameters like austenite volume fraction (Vg, its carbon content (Cg), lattice parameter, and the average cell size of the ferrite are ascertained. Electron backscattered diffraction (EBSD) analysis is used to identify the carbide precipitation obtained due to the austempering Stage-II reaction. It is noticed that, at the end of the austempering Stage-II reaction, there is a significant reduction in the volume fraction of stabilized austenite and it’s carbon content, as the microstructure at this stage not only contains ausferrite but also additional precipitated iron carbides. With an increase in austempering time, the austenite and ferrite volume fraction increase until the austenite becomes stabilized with sufficient carbon. The increase in the lattice parameter of the austenite during austempering corresponds to the rise in carbon content within the austenite. A rise in the austempering temperature leads to a reduction in the volume fraction of the ferrite and an increase in the stabilized austenite volume fraction. The optimum isothermal transformation period for austempered ductile iron is established, based on the period during which the maximum content of the austenite volume fraction, its carbon, the lattice parameter, and the average cell size of the ferrite are maintained.

/pdf/optimization-of-isothermal-transformation-period-for-4s6jkhhy7y.pdf

Optimization of isothermal transformation period for austempered ductile iron

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Prashant Parhad

Author Tools

Chat about Author

Papers

The Effect of Cutting Speed and Depth of Cut on Surface Roughness During Machining of Austempered Ductile Iron

The impact of cutting speed and depth of cut on cutting force during turning of austempered ductile iron

Effect of Austenitization Temperature on Wear Behavior of Carbidic Austempered Ductile Iron (CADI)

Effect of Austenitization Temperature on Wear Behavior of Carbidic Austempered Ductile Iron (CADI)

Optimization of isothermal transformation period for austempered ductile iron