Showing papers on "Gray iron published in 2003"

High tensile strength gray iron alloy

Abstract: A gray iron alloy having a composition comprising about 4.10% to about 4.25% carbon equivalent, about 3.5% to about 3.65% carbon, about 0.4% to about 0.9% manganese, about 1.5% to about 1.9% silicon, less than about 0.12% phosphorous, less than about 0.17% sulfur, about 0.6% to about 0.8% molybdenum and about 0.3% to about 0.6% copper, and where said carbon is predominantly present as free carbon having a Type A flake graphite microstructure. The alloy is particularly useful in the manufacture of brake drums and other articles requiring a combination of high tensile strength and good thermal conductivity.

Titanium in the rapidly cooled hypereutectic gray iron

Abstract: The effect of titanium on the structure and properties of a rapidly cooled hypereutectic cast gray iron has been studied on the example of permanent mold (PM) casting. A microstructure study showed that titanium is a relatively strong element in controlling solidification structure by increasing undercooling and thus promoting type D graphite. The effectiveness of titanium additions depends on the base iron carbon equivalent (CE) with more pronounced changes in iron with a lower CE. The undercooling ability of the titanium decreases after exceeding a certain level. Increasing titanium from 0.09–0.12% slightly increases undercooling in iron with lower CE, but this effect was reduced in a more strongly hypereutectic iron. Alloying with titanium generally improves tensile strength, but the effectiveness of titanium additions also depends on the base iron CE range. Scanning electron microscope (SEM) studies revealed that most of the titanium-containing compounds were located in the metallic matrix: titanium carbides have been found in pearlite, while titanium nitrides and carbonitrides were located in ferrite. The presence of large amounts of extremely hard titanium-containing compounds, which often appear with steadite in a relatively high phosphorous content PM gray iron, amplifies the negative effect of titanium on machinability. This study suggests that for optimal combination of tensile strength/microstructure with good machinability, the titanium content in PM gray iron should not exceed 0.075%.

A statistical study on the relationship between tensile strength and ultrasonic velocity of cast iron

Abstract: One of the most recent goals of metallurgists is to predict mechanical properties of cast iron through computer simulation. Recent research has shown that the mechanical property map of gray and du...

Development of a Cast Iron Fatigue Properties Database for use with Modern Design Methods

Abstract: A reliable and comprehensive database of design properties for cast iron is key to full and efficient utilization of this versatile family of high production-volume engineering materials. A database of strain-life fatigue properties and supporting data for a wide range of structural cast irons representing industry standard quality was developed in this program. The database primarily covers ASTM/SAE standard structural grades of ADI, CGI, ductile iron and gray iron as well as an austempered gray iron. Twenty-two carefully chosen materials provided by commercial foundries were tested and fifteen additional datasets were contributed by private industry. The test materials are principally distinguished on the basis of grade designation; most grades were tested in a 25 mm section size and in a single material condition common for the particular grade. Selected grades were tested in multiple sections-sizes and/or material conditions to delineate the properties associated with a range of materials for the given grade. The cyclic properties are presented in terms of the conventional strain-life formalism (e.g., SAE J1099). Additionally, cyclic properties for gray iron and CGI are presented in terms of the Downing Model, which was specifically developed to treat the unique stress-strain response associated with gray iron (and to a lesser extent with CGI). The test materials were fully characterized in terms of alloy composition, microstructure and monotonic properties. The CDROM database presents the data in various levels of detail including property summaries for each material, detailed data analyses for each specimen and raw monotonic and cyclic stress-strain data. The CDROM database has been published by the American Foundry Society (AFS) as an AFS Research Publication entitled ''Development of a Cast Iron Fatigue Properties Database for Use in Modern Design Methods'' (ISDN 0-87433-267-2).

Method of production of composite iron castings

Abstract: FIELD: foundry, relating to production of composite iron castings by special methods of casting SUBSTANCE: method includes making of inserts from alloying composition, gluing-them in polystyrene foam pattern, making of mold and filling of mold with molten gray iron Inserts are made of mixture with the following-amounts of components, wt%: powdery magnesium 2-4; cryptocrystalline graphite 3-4; ferrochromium VaCr 650 or VaCr 800 2-3; polystyrene 15-2; the balance, ferratitanium with titanium content of 60-68% Materials comprising insert composition provide for proceeding of self-propagating high-temperature synthesis in filling of mold with liquid iron Reaction proceeds with liberation of large amounts of heat EFFECT: improved conditions of formation in iron castings of wear-resistant hard-alloy surface layer and high-strength transition layer 1 tbl

Influence of Titanium on Structure and Properties of D-type Graphite Cast Iron

Abstract: Abstrace:The influence of titanium on the structure and properties of gray iron was investigatedExperi-ments showed that the titanium of different contents had varied influences on the structure and proper-ties of gray ironIn certain range of content s,titanium had the effect to promote formation of the D-type graphite,to improve the graphite morphology of gray iron and increase properties of gray ironThe mechanism of the effect of titanium on structure and properties of gray iron was proposed