Malleable Iron Research Articles

Assessment of foundry properties of steel casting sand moulds bonded with the grade 4 Nigerian acacia species (gum arabic).

Gum Arabic is a plant gum exuded from bark of some species of trees called acacia species. Nigeria produces four different grades of material. Nigeria, the second largest producer in the world has no registered commercial uses for it. This research investigated the viability of casting steel in sand moulds bonded with grade 4 Nigerian gum Arabic. Sand specimens bonded with the material were subjected to standard foundry property analyses that included green and dry compressive strength, hardness and permeability, shatter index and moisture content tests. The result when compared to standard showed that 4.5 - 8.0% binder content in powdered form is suitable for casting non-ferrous alloys, malleable and grey iron while 8 - 13% is suitable for light steel. In solution form it is suitable for non-ferrous alloy. Key words: Steel casting, foundry properties, gum arabic exudates.

A new solution for automatic microstructures analysis from images based on a backpropagation artificial neural network

This article presents a new solution to segment and quantify the microstructures from images of nodular, grey, and malleable cast irons, based on an artificial neural network. The neural network topology used is the multilayer perception, and the algorithm chosen for its training was the backpropagation. This solution was applied to 60 samples of cast iron images and results were very similar to the ones obtained by visual human tests. This was better than the information obtained from a commercial system that is very popular in this area. In fact, this solution segmented the images of microstructures materials more efficiently. Thus, we can conclude that it is a valid and adequate option for researchers, engineers, specialists, and professionals from materials science field to realise a microstructure analysis from images faster and automatically.

Failure analysis of galvanized iron pipeline accessories of a fire protection system

In the present work, the failure of galvanized iron pipes accessories has been analyzed. These accessories are part of a fire protection system in an industrial building. It has been observed the confluence of several circumstances, as defects in the design or in the execution of the installation, false alarms with filling of the pipe installation, geometry of the accessories made in malleable white-heart cast iron and inherent superficial defects of this type of accessories, that have lead to the sudden failure of an elevated number of such accessories during one of the fillings of the installation. An exhaustive macro and micrographic analysis has been done, in order to identify the combined fracture micro-mechanisms observed for this material.

旋削加工におけるMQLの効果

In this paper, the MQL turning of two types of ferrous metals: chromium-molybdenum steel SCM440H and pearlite malleable cast iron FCMP: is dealt with. The appropriate generating system of oil mist is constructed and the specified turning tool with oil hole is used. In order to verify the cooling effect of MQL, the tool temperature at the flank face is measured using a newly assembled fiber-coupled two-color pyrometer. In this new technique, a sensing fiber is inserted into a small hole that extends to the outer surface of the tubelike workpiece and it rotates with the workpiece. The thermal radiation accepted by a sensing fiber is noncontactly transmitted to the other fixed fiber and led to the two-color detectors. As for cutting force in turning of SCM440H, MQL is more effective in low cutting speed below 100 m/min. The tool temperature in MQL turning is approximately 100°C lower than that in dry turning over the wide range of 30∼300 m/min. In the case of FCMP, the tool temperature in dry turning at a cutting speed of 600 m/min reaches as much as about 1040°C, but it drops 920°C in MQL turning.

Influência do bismuto, níquel, estanho e alumínio na espessura da camada dos revestimentos galvanizados

Conexões de ferro fundido maleável preto foram galvanizadas em dezesseis diferentes banhos de zinco, cada qual composto por concentrações e combinações variadas de bismuto (0,06 e 0,1%), níquel (0,003 e 0,05%), estanho (0,3 e 0,5%) e alumínio (0,01 e 0,14%). Os revestimentos obtidos foram estudados através de medidas de espessura de camada, análise metalográfica utilizando microscopia ótica e microanálise utilizando espectrometria de energia dispersiva de raios-x (EDS). Obtiveram-se algumas variações na espessura e na morfologia do revestimento com as diferentes ligas, onde cada elemento químico interferiu de uma forma, contribuindo ou não para a formação de um revestimento menos espesso. O bismuto influenciou na fluidez do banho de zinco, o estanho na formação dos compostos intermetálicos e o alumínio através da formação do composto Fe2Al5 inibiu a reação do zinco com o ferro. Entretanto, o níquel não interferiu positivamente na reatividade, não participando então da redução do revestimento galvanizado. Os elementos adicionados ao banho de galvanização apresentaram-se efetivos na diminuição da espessura do revestimento proporcionando assim uma economia de zinco, sendo ainda uma boa alternativa para substituir o chumbo, um elemento químico considerado nocivo ao meio ambiente.

Effects of Copper and Malleablizing Time on Mechanical Properties of Austempered Malleable Iron

In this study, both the unalloyed and 1 wt pct copper alloyed white irons were successively treated with a duplex heating process consisting of malleablizing and austempering, and then the effects of copper and processing variables on microstructure and mechanical properties of the austempered malleable iron (AMI) were investigated. The results showed that AMI could effectively shorten malleablizing time to obtain the constituents of irregular graphite, acicular ferrite, and retained austenite in the microstructure. Moreover, 1 pct Cu-AMI had a higher retained austenite content than unalloyed AMI. This is because copper is an austenite stabilizer and acts to delay the start of the transformation into ausferrite. In the case of mechanical properties, AMI increased tensile strength (1083 to 1190 MPa) and impact toughness (16 to 22 J) by 2 to 3 times after 930 °C–20 hours malleablizing treatment as compared to as-cast (572 to 580 MPa and 5 to 6 J). In particular, 1 pct Cu-AMI had better performance than unalloyed AMI except for hardness. In comparison with conventional malleable irons, AMI was found to possess better tensile and impact properties.

Monte Carlo simulation of microstructure in malleable cast iron after austempering

Structures formed in malleable cast iron in the process of austempering are simulated with the help of the Monte Carlo method. The simulation is performed using a matrix consisting of 150 × 150 regions. The length of each region is 0.1 µm; the simulated area is 1 × 1 mm in size. The grain sizes obtained in the model and in experiments match satisfactorily.

Preparation of White Heart Malleable Cast Iron in Na<SUB>2</SUB>O-K<SUB>2</SUB>O-SiO<SUB>2</SUB> Oxide Molten Salt

The preparation process of white heart malleable cast iron by heat treatment of white cast iron in Na 2 O-K 2 O-SiO 2 oxide molten salts at lower temperature than usual production method was studied. The liquidus temperature of the K 2 O added Na 2 O-SiO 2 (64-36 mol%) system was measured by the hot-thermocouple method and the effect of the treatment temperature on the degree of decarburization of white cast iron was investigated. The result of measuring liquidus temperature indicated that the Na 2 O-K 2 O-SiO 2 (38.4-40-21.6mol%) ternary oxide melted at about 893 K. After heat treatments of white cast iron (08 mm x 8 mm) containing 3.34 mass% carbon in this oxide molten salt at 1123-1223 K for 72 h, the white heart malleable cast iron could be obtained. Although, the thickness of the surface decarburized layer decreased with the decrease of the treatment temperature, the white heart malleable cast iron having about 30 μm surface layer was obtained even at low temperature of 1123 K. The basicity of this molten salt was 2.53, which was too high to be suitable for the decarburization of white cast iron at 1323 K. It is found that white heart malleable cast iron can be prepared by the heat treatment in high basisity oxide molten salt at lower temperature than 1323 K.

European Community – Antidumping Duties on Malleable Cast Iron Tube or Pipe Fittings from Brazil (WT/DS219/AB/R: DSR 2003:VI, 2613)

This chapter addresses the Appellate Body (AB) report on European Community – Antidumping Duties on Malleable Cast Iron Tube or Pipe Fittings from Brazil. The underlying Panel determination was appealed by the complainant Brazil only. Following the approach it took before the Panel, Brazil raised a number of issues concerning the antidumping investigation by the European Community (EC).

Preparation of White Heart Malleable Cast Iron in Na<SUB>2</SUB>O–SiO<SUB>2</SUB> Oxide Molten Salt

Preparation of White Heart Malleable Cast Iron in Na<SUB>2</SUB>O–SiO<SUB>2</SUB> Oxide Molten Salt

Deformation and Strength of Malleable Cast Iron in the Complex Stressed State

We analyze the experimental data on the specific features of deformation, damageability, and strength of malleable cast iron obtained in testing tubular specimens under conditions of simple loading by axial forces and internal pressure. It is shown that the degradation of the structure of the material depends on the parameters of the stressed state. New criteria required for the description of the limiting states of yield and fracture are established.

Elasto-plastic hemispherical contact models for various mechanical properties

This work uses the finite element technique to model the elastoplastic deformation of a hemisphere contacting a rigid flat for various material properties typical of aluminium, bronze, copper, titanium and malleable cast iron. Additionally, this work conducted parametric finite element method (FEM) tests on a generic material in which the elastic modulus and Poisson's ratio are varied independently while the yield strength is held constant. A larger spectrum of material properties are covered in this work than in most previous studies. The results from this work are compared with two previously formulated elastoplastic models simulating the deformation of a hemisphere in contact with a rigid flat. Both of the previously formulated models use carbon steel mechanical properties to arrive at empirical formulations implied to pertain to various materials. While both models considered several carbon steels with various yield strengths, they did not test materials with various Poisson's ratios or elastic moduli. The previously generated elastoplastic models give fairly good predictions when compared with the FEM results for various material properties from the current work, except that one model produces more accurate predictions overall, especially at large deformations where other models neglect important trends due to decreases in hardness with increasing deformation.

マイクロX線法によるドライ電動摺動部品の強度信頼性保証

By the leather film given to the malleable iron of the plunger used for solenoid currently used for all apparatus, such as optics, medical treatment, and automobile relation, including information machines and equipment or office apparatus, since there are problems, such as low intensity, using oil, the new surface coating technology which gave highly efficient nature is searched for. Then, by this research, the oilless high efficiency leather film of high intensity is coating, and it carries out by considering-influence of remains stress mechanism of the leather film and basis material on-the-strength reliability guarantee.

A New Look at Cast Iron Microstructure

Abstract Cast irons belong to a family of iron-carbon (Fe - C) alloys with free carbon in the form of graphite, a very soft constituent of iron microstructures, that improves machinability and damping properties of castings, or combined carbon, in the form of cementite, that improves wear resistance. Graphitic cast irons include grey iron, compacted iron, malleable iron, and ductile iron, Cementite irons include white cast iron and alloy cast irons. Solidification of graphite directly from molten metal takes place between 1145°C (2093 °F) and 1152 °C (2105 °F), according to the Fe-C equilibrium diagram. The above considerations regard only pure Fe - C alloys.

Baltic iron and the British iron industry in the eighteenth century

Before the revolution in coal technology that swept the British iron industry in the last years of the eighteenth century, native ironmasters were unable to meet the burgeoning demand for malleable bar iron. The shortfall was made good by imports of bar iron from the Baltic, first from Sweden, then from Russia. This article presents new empirical evidence on the role played by Baltic iron in the Georgian economy. It also considers the impact of Swedish and Russian iron on domestic ironmasters as they sought organizational, as well as technological, ways to overcome the energy constraints facing the industry.

Some Results of Investigations into High-Rate Hot Extrusion of Malleable Cast Iron

Based on the results of our investigations, an optimal temperature and strain-rate regime of high-rate extrusion is established (with strain rates V0 = 10–100 m/s, temperatures T0 = 800–1000°C, and elongations λ = 1.94–4.0) in which a deformable material (KC 37-12 malleable cast iron) manifests a high ductility. In addition, the mechanical properties – the compression strength σcs and the Brinell hardness – increase 2–3 times compared to those of cast specimens. Based on the data obtained, a novel method of rod extrusion from malleable cast iron has been developed.

Quantitative Analysis of the Relation Between the Microstructure and the Magnetic Properties of “Nippel' 1 1/4"” Workpiece Castings Made of KCh-30-6 Malleable Cast Iron

It is found a quantitative relation between the microstructure (ferrite percentage) of castings of pieces of the “Nippel' 1 1/4"” type made of KCh-30-6 malleable cast iron and the records of a device called “Magnetic analyzer of the product structure quality Maksi-PM” which is used at the Minsk Heating Installation Works for the machine testing of machinability of castings. The thresholds of the readings necessary for presorting the nipple castings into suitable for the mechanical operation, conventionally suitable (for operation at reduced cutting rates), and defective are refined. The possible reasons of violation of the casting structure in the stable manufacturing process are analyzed.

New PM alloys to replace malleable cast iron

Decarburization of two white cast irons, differing only in microstructure, has been studied using a 20% carbon dioxide-80% carbon monoxide atmosphere. Carbon loss and depth of decarburization at 1000°C and 1050°C were measured as a function of time. A mathematical analysis of decarburization is developed and from a comparison of this with the experimental results it is concluded that the diffusion of carbon in austenite is the rate controlling process.Les auteurs étudient la décarburation de deux fontes blanches se différencient uniquement par leur microstructure. Ils utilisent un mélange gazeux contenant 20% d'anhydride carbonique et 80% d'oxyde de carbone. Ils déterminent la perte en carbone et la profondeur de décarburation en fonction du temps.Ils font ensuite l'analyse mathématique de ce phénomène et en comparant avec les résultats expérimentaux déduisent que la diffusion du carbone dans l'austénite détermine la vitesse de décarburation.Die Entkohlung von zwei Sorten weiβen Guβeisens, die sich nur in der Mikrostruktur unterschieden, wurde in einer Atmosphäre von 20% Kohlendioxyd und 80% Kohlenmonoxyd untersucht. Kohlenstoffverlust und Tiefe der Entkohlung wurden bei 1000°C und 1050°C als Funktion der Zeit gemessen. Eine mathematische Beschreibung der Entkohlung wird entwickelt; aus einem Vergleich mit den experimentellen Ergebnissen läβt sich dann schlieβen, daβ die Diffusion von Kohlenstoff in Austenit der geschwindigkeitsbestimmende Prozeβ ist.

Survey of available data for pressure loss coefficients, ζ, for elbows and tees of pipework

Although numerous data are available for pressure loss factors for ductwork components, the factors for pipework components have not received the same attention. Gross simplifications and contradictions are found in surveys of available published data from the USA, Britain and continental Europe. Some is repeated from research conducted nearly 70 years ago and extrapolated into areas that were not investigated. It was first necessary to disregard that which is least reliable so as to be able to select what might be considered the most reliable. It is regrettable that it is inevitably necessary to discard data published specifically with the intention of helping engineers; it is hoped that no offence is caused. For laminar flow, data were found that had not appeared in any simplified guide. For turbulent flow, there is a case to be made for a re-investigation of the pressure loss factors that occur with standard manufactured components, since some of the best data are taken from generalised work on larger dimensions artificially roughened to simulate pipework. The only data considered as reliable for tees concern tees made of malleable iron. Until further information is available, it is suggested that this will need to be used also for fittings of other materials. Although data for pipe elbows are size dependent, those for tees are not.

Fractal growth of graphite nodules in iron

It has been found from a large number of statistical tests that graphite nodules in malleable iron grow with time according to a power law. The growth of the nodules and their fractal dimension have been investigated experimentally as a function of annealing time. Based on the assumption of carbon-diffusion-controlled growth in the initial stage, the growth equation is R G = K 1 t 1/(D-1), where R G is the radius of the graphite nodules, t the time, D the fractal dimension and K 1 a constant. Assuming cementite-dissolution-controlled growth in the later stages of growth, the relation is R G = K 3 t 3/D , where K 3 is a constant. The fractal dimension, or the aggregate state of the graphite nodules, strongly influences the growth process.