Ductile iron castings are produced for applications requiring strength, toughness, good machinability, and low cost. Ductile iron fittings for pressure ratings of 150, 250 and 350 psi are furnished as shown in the tables in this section. Syi manufactures a full range of ductile iron pipe fittings according to iso 2531, en545, en598, en 12842, gb 295, ansiawwa c110, c153 and other major standards. As 1831 2007 is an australian standard for ductile cast iron. Solidification and microstructure of thin walled ductile cast iron. The main objective of the current work is to investigate the influence of different inoculation conditions on the microstructure and mechanical properties of heavy section ductile iron di castings. The mechanical properties of the fabricated samples were evaluated. This alloy is available in several qualities, from tough ferritic to strong and hard pearlitic. It is a comprehensive summary of data describing the engineering properties of ductile iron. Ductile iron data for design engineers table of contents preface i. The objective of this paper was to study the effect of austempering time and. It contains spheroid graphite in the as cast condition, through the addition of nucleating agents such as cerium or magnesium to the liquid iron 2, 4. Radzikowska, the foundry research institute, krako. Effect of graphite nodularity on mechanical properties of.
Weldability of spheroidal graphite ductile cast iron using. Ductile iron is known for its ductility and toughness after special magnesium, cerium, lanthanum treatment. Comparison of the mechanical properties of steel and ductile. Quenching and partitioning process in ductile cast irons. Ductile iron contains spheroidal nodular shaped graphite, is higher strength than gray iron, and weighs about 10% less than steel for the same section size. Ductile iron pipe field rounding procedure ovality is a fact of pipe. Even since its discovery in 1948, the use of ductile iron is increasing continuously, this is. Annealed cast ductile iron can be bent, twisted or deformed without fracturing. Offsetting shrinkage in ductile iron what thermal analysis shows by david sparkman may 30, 2001 last revision february 11 th 2006 abstract the natural shrinkage that occurs during the solidification of ductile iron can be. The effect of ductile cast iron matrix on zinc coating.
Ductile iron is made by increasing the amount of carbon in iron. Austempered ductile iron is ductile iron that has been austempered in order to improve properties, such as strength, wear resistance or noise damping. Nodular cast iron hereafter called nci is an engineering material displaying high ductility, elastic modulus, mechanical strength and. It is an alternative to traditional steel castings and forgings and even. Effect of copper on austempering behavior of ductile iron core. Ductile iron data for engineers preface ductile iron data for design engineers revised edition. An ascast ductile iron casting is normalized in order to.
The common defining characteristic of this group of materials is the shape of the graphite. Because the data overlaps in some instances, only the regressions lines. These and other standards are referenced throughout this section either by the full ansiawwa designation or by only the awwa numbering, such as awwa c110 or c153. Austempered ductile iron adi is a relatively new engineering material with exceptional combination of mechanical properties and marked potential for numerous applications. Benefits of ductile iron pipe ductile iron versus pvc ductile iron versus steel environmental benefits sustainable pipe certification the truth about cementmortar lined pipe the truth about epds vbio enhanced polyethylene encasement vbio enhanced polyethylene encasement patents bonded coatings versus polyethylene encasement buried no longer corrosion control dangers of using pvc. Solution strengthened ferritic ductile irons ssf ssf cast iron is a high strength ductile cast iron quality alloyed with silicon between 3. Inoculation treatment was done via one step and double step treatments with different amounts of inoculants. However, pure iron is a poor engineering material, generally not as strong as most plastics. Abrasion resistant iron data from the abrasionresistant cast iron handbook. Effect of graphite nodularity on mechanical properties of ductile iron for waterworks fittings and accessories a. This alloying level of silicon is constant per ssfgrade, unlike. The surface layer of austempered ductile iron investment.
Normalizing involves the austenitizing of a ductile iron casting, followed by cooling in air through the critical temperature. A series of samples made of ductile iron gjs 400 was cast with different cooling rates, and their microstructural features were. Austenitic ductile iron for low temperature applications afe. Class ductile iron pipe weights for pipeline design weight of ductile iron pipe and contained water table no. This promotes the precipitation of graphite in the form of. Austempered ductile iron castings, or adi castings are ductile iron castings processed by a special heat treatment. Flanged pipe fittings loosing flanged pipe fittings. Corrosion is the manifestation of the second law of thermodynamics, entropy, the inexorable march toward disorder. September 28, 2014, cherran, comments off on what is ductile iron ductile iron is also known as spheroidal graphite or nodular iron.
The title describes both the contents and the objective of this book. This high value results from many factors, one of which is the control of microstructure and properties that can be achieved in the ascast condition, enabling a high. It is not intended to be a complete textbook or handbook on ductile iron. Ductile cast iron according to en 1563, sometimes referred to as spheroidal graphite cast iron has very good mechanical properties. Ductile iron is a type of cast iron known for its impact and fatigue resistance, elongation, and wear resistance due to the spherical round graphite structures in the metal. This is not an indication of bad pipe, just one that has been heat. Weldability of spheroidal graphite ductile cast iron using ni nife electrodes m. Comparison of the mechanical properties of steel and. The results described in this paper show that unalloyed ductile iron. Elwakil1,4 abstract waterworks fittings and accessories are important applications for ductile irons. Austempered ductile iron production properties applications 1. Making it an excellent alternative to steel, even in dynamically loaded applications. Stringent requirements concerning mechanical properties at low temperatures are satisfied, first and foremost, by the highnickel cast iron of austenitic matrix.
Abstract austempered ductile iron adi is a type of graphite cast iron produced by an isothermal heat treatment process. Modeling cast irons has always been a special challenge due to the strong interdependency between the alloy composition, applied metallurgy and metal. The effect of austempering on the microstructure and toughness of nodular cast iron designated as cunimosg alloyed with molybdenum, copper, nickel, and manganese has been studied. Successfully machining austempered ductile iron adi. Ductile iron also consists of nodular graphite, which gives it flexibility. The attractive properties of adi return to its distinct and unique microstructure, which consists of fine acicular ferrite within cenriched stabilized austenite.
Therefore, this reaction should be avoided during heattreatment. The youngest but most successful member of a truly ancient family, ductile iron has suffered from an abundance of myths and a lack. This specification is similar to astm a536 grade 1007003. Ductile iron, also known as ductile cast iron, nodular cast iron, spheroidal graphite iron, spheroidal graphite cast iron and sg iron, is a type of graphiterich cast iron discovered in 1943 by keith millis. The manufacture and process control of ascast ductile iron are discussed. The effect of ductile cast iron matrix on zinc coating during. Design for ductile iron pipe presented suggested design procedures for the restraint of thrust forces in pressurized, buried ductile iron piping systems. The objective of this standard is to specify grades of ductile cast irons by mechanical properties. Pdf articles ductile iron for heavy section wind mill castings. These weights are based on minimum class ductile iron pipe with minimum thickness standard cement lining as specified in awwa c104 and on weight of water of 62. Metallography and microstructures of cast iron janina m.
Ductile iron pipe fittings syi pipeline corporation. Mechanical joint fittings are normally furnished complete with a gland, plain rubber gasket, and tee head alloy steel bolts with heavy hex nuts for each socket. In fact ductile cast iron provides a wide spectrum of mechanical. Ductile iron data for design engineers revised edition. Chapter 6 ductile iron production of ductile iron ductile iron, also known as spheroidal graphite s. Mar 19, 2012 austempered ductile iron production properties applications 1. Mechanical and structural properties of ductile cast iron. Introduction one reason for the phenomenal growth in the use of ductile iron castings is the high ratio of performance to cost that they offer the designer and end user.
Elwakil1,4 abstract waterworks fittings and accessories are important applications for. The austemper heat treatment is an isothermal process that transforms the metal matrix over many minutes or hours, culminating in properties that give the component better performance and strength. Microstructure influence on fatigue crack propagation resistance in five different ductile cast ironsdci was investigated. The level of carbon added to iron exceeds its solubility limits and as it solidifies. Ductile cast iron has good mechanical properties but it is necessary to re duce the wall. Durabar ductile iron is a costsaving alternative to lowmedium carbon steels and has similar strengths with excellent free machining properties. Light microscopy lm, scanning electron microscopy sem, and xray. Flange surfaces shall be faced and drilled in accordance with ansi class 125, b16. Ductile iron is often made from scrap, pig iron and recycled ductile iron. Ductile iron is not a single material but part of a group of materials which can be produced with a wide range of properties through control of their microstructure.
The pearlitic structure maximizes strength and wear characteristics in a nonalloyed ascast ductile iron. All ductile iron flanged fittings shall be rated for water pressure of 250 psi. Compact ductile iron fittings are covered in ansiawwa c153a21. Fittings for water service are generally furnished with cement. What are the advantages of concast ductile iron compared with other materials. The basic difference between steel and cast iron is the amount and nature of the contained carbon. Ductile iron is also called ductile cast iron, spheroidal graphite cast iron, or nodular cast iron. But one cannot make out different shapes and forms using cast iron. The role of microstructure on tensile plastic behavior of ductile.
American ductile iron mechanical joint fittings the principal standards covering full body mechanical joint fittings are ansiawwa c110a21. Ductile iron can be bent without breaking, whereas cast iron is brittle and breaks when bent. This promotes the precipitation of graphite in the form of discrete nodules instead of interconnected flakes fig. Ductile iron what ductile iron is ductile iron is a family of cast graphitic irons which possess high strength, ductility and resistance to shock.
American ductile iron flanged fittings the principal standard covering flanged fittings is ansiawwa c110a21. Kwiatkowskib a institute of manufacturing technology, warsaw university of technology, poland b institute of precision mechanics, poland email. Sep 04, 2001 like grey iron, ductile iron is an iron carbonsilicon alloy. While most varieties of cast iron are weak in tension and brittle, ductile iron has much more impact and fatigue resistance, due to its nodular graphite inclusions. Microstructures that develop during solidification of a ductile iron casting are to. Effects of niobium addition on microstructure and tensile. Typical carbon content is in the range 3 to 4%, while silicon content is slightly higher than grey iron at 2 to 3%.
Recommendations for ductile and brittle failure design. Microstructure and toughness of cunimo austempered ductile. En 1563 new generation ductile irons solid solution strengthened ductile irons. Internal stress contained in the metal wall from the foundry annealing process can be released when cutting a pipe, causing the pipe to spring outofround. There is very little difference in machinability between this grade and 654512 and is rarely used because of the added cost of heattreating. The primary objective of this guide is to assist producers of ductile iron castings in obtaining higher levels of quality reliability. As ductile iron can be bent, it can be made into different shapes and forms.
The outstanding properties of ductile iron are due to a nodular or spheroidal form of precipitated graphite in the microstructure. Cast irons are based on the fec system, and the solidstate transformations on which cast iron heat treatments are based are similar to those applied to steels. Four ferritepearlite volume fractions were considered, performing. A galvanic series showing less noble anodic metals to the left and more noble cathodic metals to the right. Recent development of ductile cast iron production technology in. The surface layer of austempered ductile iron investment castings properties d. This is because they are much stronger than cast iron. Melt was prepared in medium frequency induction furnace from pig iron, steel scrap, and ductile cast iron returns. Benefits of ductile iron pipe ductile iron versus pvc ductile iron versus steel environmental benefits sustainable pipe certification the truth about cementmortar lined pipe the truth about epds vbio. Microstructure and mechanical properties of cunimo. Weldability of spheroidal graphite ductile cast iron using ni.
Nuclear regulatory commission is developing regulatory guides for the design of, and the qualification for acceptance of, ductile cast iron shipping containers. Welding of ductile iron with nifemn filler metal a new filler metal system can be used with several welding processes to produce joints in ductile iron that match or exceed base metal properties up to 80,000 psi 552 mpa by t. Their results showed that the nb addition in ductile iron provided significant enhancement in mechanical properties when. Offsetting shrinkage in ductile iron ver 2 meltlab. The microstructure, properties and application of partial austenitization normalizing. Moreover, ductile iron is better than cast iron in difficult terrains. Rayon abstract weldability of spheroidal graphite ductile cast iron was established using a cheap nife and a high purity ni electrode. Ductile iron microstructure by thermal analysis one promising new technology is the rapid classification of microstructure by thermo analysis. At the same time, technical literature lacks the description of broad and comprehensive researches on various reactions that take place during hot dip galvanising of ductile iron, especially as regards. Strength and durability for life ductile iron pipe. This form of graphite favours the elasticity of the cast iron and increases its inherent strength. Durabar 1007002 ductile iron contains nodular graphite in a matrix of pearlite with small amounts of ferrite. En 1563 new generation ductile irons solid solution. The effect of ductile cast iron matrix on zinc coating during hot dip galvanising of castings d.
In ductile irons, graphite is in the form of nodules rather than flakes as in grey iron. Mechanical and microstructural characterization of nodular cast. Its strength, toughness and ductility duplicate many grades of steel and far exceed those of standard gray irons. Effect of solidification time on microstructural, mechanical. The austempering process results in ductile iron which can be used to cast complex shapes, with a greater consistency of quality, and often at less cost. Flanged fittings, 2 through 48 shall be manufactured of ductile iron in accordance with all applicable terms and provisions of standards ansiawwa c110a21. To demonstrate the distinguishing mechanical properties of steel and ductile iron, large diameter samples were gathered, cut, and subjected to mechanical property testing. In their bid to produce cast iron latter than malleable iron, the scientist discovered the ductile iron or s. It is also common for ductile irons to contain significant additions of nickel. These and other standards are referenced throughout this section either by the full. This standard is identical with, and has been reproduced from iso 1083. For ductile iron, because its carbon content is high enough, 3. Austempered ductile iron production properties applications. Carbon forms spheroidal particles instead of sheets.