Die Casting’s Blog

Automotive components made by aluminum die casting, gravity casting, sand casting, or machining directly from stock bar. Quality system TS16949, quality control plan, PPAP procedure to be sure the high quality components used for Auto Industry.

Automotive Components Automotive Components

Automotive Components Holdings is a temporary company managed by Ford, established in October 2005 with former Visteon component operations. ACH’s mission is to ensure the flow of quality components and systems while preparing the ACH automotive component operations for sale or idling. The $4 billion company and its 12 plants are currently supported by about 12,000 full-time employees, mostly leased from Visteon or Ford.

Richard Newsted, Meridian’s president and CEO said, “Acquiring the Sandusky, Ohio facility is a logical extension of our engineering and manufacturing expertise in lighting.”

“We are excited about the opportunity to improve the long-term competitive position of this operation and expand our strengths and capabilities in lighting technology.”

The sale is contingent upon reaching a new and competitive agreement with the United Auto Workers.

One of the most efficient and economical means of shaping metal into a particular form is called casting- a process in which metal is heated to a molten state can be poured into a mold of choice and left to harden by foundry workers. Malleable iron is made from white cast iron by “cooking” it at temperatures from 1,500 too 1,850 degrees Fahrenheit over several days. This enables the iron carbide to break up, producing rosettes of graphite in the process. This particular iron is known for it’s strength, pliability, shock resistance, and it’s ability to be machined. This is one of the more popular ways of producing engine blocks, valves and iron ornaments among other items for the automotive and agricultural industries, plus many bits and pieces for the military.

Even on the most blustery winter day with every window open, casting iron is very hot, sweaty work. The temperatures of the raw materials heating up to an average of 2,850 degrees Fahrenheit (or more) can have quite the warming effect within the surrounding atmosphere.

In recent years, both the iron casting and the automotive industries have gone through some significant changes. For starters, the current higher than expected oil prices have created a demand for a smaller, lighter style of passenger vehicle. The result is a rise in car imports, leaving the Sport Utility Vehicle (SUV) market and it’s heavy, automotive parts with a less than positive outlook. New fuel economy standards are expected to drive the renovation of iron blocks, suspension castings and carriers to aluminum in light trucks and increase the development of all lightweight metals.

Many believe that iron casting is just simply out of reach for small furnaces but this is not the case. While alloys like aluminum are more prevalent in home foundries. Artists and hobbyists have also used brass, bronze, and even iron to fulfill their casting needs.

Industrial foundries commonly use iron for a variety of items like cookware, like cast iron pans, and even bridges. Casting iron provides an easy and effective method of making such large structural pieces and even smaller pieces for around the home.

The most common furnace type used by home foundries is the cupola furnace. The cupola is a basic furnace type that does not need a crucible as it allows the caster to pour the molten metal directly from the furnace into a ladle which is then poured into the mold. Cupola furnaces resemble smoke stacks and can be home made for those with enough confidence and some mechanical know-how to attempt it. The fuels used to heat the metal in a cupola furnace depend on the caster’s resources and preference. Many will use propane and some will use coal. There are a select few that will use waste material such as old scraps of metal and the powder at the bottom of bags of barbecue coal to fuel the cupola. For iron many would recommend the use of propane, but there have been some casters that have succeeded with waste material. Don’t be afraid to experiment with different fuel types to find the perfect fit for your furnace and need. mould design

Finding a source of iron can be difficult and a trip to the scrap yard might be in order. This is just one of the exciting ventures that metal casting can provide you. After you locate your iron you will need to prepare your mold. This is assuming you have a pattern in mind that you want to cast. If not, then go ahead and figure something out even if it’s a small piece in order to test your iron casting ability. Since sand casting is the most popular casting method you might want to use it for the iron casting especially if you are familiar with the method and not with iron. Steel Casting

MacKenziein his l944 Howe Memorial Lecture referred to cast iron as “steel plus graphite.” Although this simple definition still applies, the properties of gray iron are affected by the amount of graphite present as well as the shape, size, and distribution of the graphite flakes. Although the matrix resembles steel, the silicon content is generally higher than for cast steels, and the higher silicon content together with cooling rate influences the amount of carbon in the matrix. Gray iron belongs to a family of high-carbon silicon alloys which include malleable and nodular irons. With the exception of magnesium or other nodularizing elements in nodular iron, it is possible through variations in melting and foundry practice to produce all three materials from the same composition. In spite of the widespread use of gray iron, the metallurgy of it is not clearly understood by many users and even producers of the material. One of the first and most complete discussions of the mechanism of solidification of cast irons was presented in 1946 by Boyles^[2]. Detailed discussions of the metallurgy of gray iron may be found in readily available handbooks^[3-7]. The most recent review of cast iron metallurgy and the formation of graphite is one by Wieser et al^[8]. To avoid unnecessary duplication of information, only the more essential features of the metallurgy of gray iron will be discussed here.

Gray iron casting is commercially produced over a wide range of compositions. Foundries meeting the same specifications may use different compositions to take advantage of lower cost raw materials locally available and the general nature of the type of castings produced in the foundry. For these reasons, inclusion of chemical composition in purchase specifications for castings should be avoided unless essential to the application. The range of compositions which one may find in gray iron castings is as follows: total carbon, 2.75 to 4.00 percent; silicon, 0.75 to 3.00 percent; manganese, 0.25 to 1.50 percent; sulfur, 0.02 to 0.20 percent; phosphorus, 0.02 to 0.75 percent. One or more of the following alloying elements may be present in varying amounts: molybdenum, copper, nickel, vanadium, titanium, tin, antimony, and chromium. Nitrogen is generally present in the range of 20 to 92 ppm.

The concentration of some elements may exceed the limits shown above, but generally the ranges are less than shown.

Carbon is by far the most important element in gray iron. With the exception of the carbon in the pearlite of the matrix, the carbon is present as graphite. The graphite is present in flake form and as such greatly reduces the tensile strength of the matrix. It is possible to produce all grades of iron of ASTM Specification for Gray Iron Castings (A 48-64) by merely adjusting the carbon and silicon content of the iron. It would be impossible to produce gray iron without an appropriate amount of silicon being present. The addition of silicon reduces the solubility of carbon in iron and also decreases the carbon content of the eutectic. The eutectic of iron and carbon is about 4.3 percent. The addition of each 1.00 percent silicon reduces the amount of carbon in the eutectic by 0.33 percent. Since carbon and silicon are the two principal elements in gray iron, the combined effect of these elements in the form of percent carbon plus 1/s percent silicon is termed carbon equivalent (CE). Gray irons having a carbon equivalent value of less than 4.3 percent are designated hypoeutectic irons, and those with more than 4.3 percent carbon equivalent are called hypereutectic irons. For hypoeutectic irons in the automotive and allied industries, each 0.10 percent increase in carbon equivalent value decreases the tensile strength by about 2700 psi.

If the cooling or solidification rate is too great for the carbon equivalent value selected. the iron may freeze in the iron-iron carbide metastable system rather than the stable iron-graphite system, which results in hard or chilled edges on castings. The carbon equivalent value may be varied by changing either or both the carbon and silicon content. Increasing the silicon content has a greater effect on reduction of hard edges than increasing the carbon content to the same carbon equivalent value. Silicon has other effects than changing the carbon content of the eutectic. Increasing the silicon content decreases the carbon content of the pearlite and raises the transformation temperature of ferrite plus pearlite to austenite. This influence of silicon on the critical ranges has been discussed by Rehder^[9].

The most common range for manganese in gray iron is from 0.55 to 0.75 percent. Increasing the manganese content tends to promote the formation of pearlite while cooling through the critical range. It is necessary to recognize that only that portion of the manganese not combined with sulfur is effective. Virtually, all of the sulfur in gray iron is present as manganese sulfide, and the manganese necessary for this purpose is 1.7 times the sulfur content. Manganese is often raised beyond 1.00 percent, but in some types of green sand castings pinholes may be encountered.

Sulfur is seldom intentionally added to gray iron and usually comes from the coke in the cupola melting process. Up to 0.15 percent, sulfur tends to promote the formation of Type A graphite. Somewhere beyond about 0.17 percent, sulfur may lead to the formation of blowholes in green sand castings. The majority of foundries maintain sulfur content below 0.15 percent with 0.09 to 0.12 percent being a common range for cupola melted irons. Collaud and Thieme^[10] report that, if the sulfur is decreased to a very low value together with low phosphorus and silicon, tougher irons will result and have been designated as “TG,” or tough graphite irons.

The phosphorus content of most high-production gray iron castings is less than 0.15 percent with the current trend toward more steel in the furnace charge; phosphorus contents below 0.10 percent are common. Phosphorus generally occurs as an iron iron-phosphide eutectic, although in some of the higher- carbon irons, the ternary eutectic of iron iron-phosphide iron-carbide may form. This eutectic will be found in the eutectic cell boundaries, and beyond 0.20 percent phosphorus a decrease in machinability may be encountered. Phosphorus contents over 0.10 percent are undesirable in the lower-carbon equivalent irons used for engine heads and blocks and other applications requiring pressure tightness. For increased resistance to wear, phosphorus is often increased to 0.50 percent and above as in automotive piston rings. At this level, phosphorus also improves the fluidity of the iron and increases the stiffness of the final casting.

Copper and nickel behave in a similar manner in cast iron. They strengthen the matrix and decrease the tendency to form hard edges on castings. Since they are mild graphitizers, they are often substituted for some of the silicon in gray iron. An austenitic gray iron may be obtained by raising the nickel content to about 15 percent together with about 6 percent copper, or to 20 percent without copper as shown in ASTM Specification for Austenitic Gray Iron Castings (A 436-63).

Chromium is generally present in amounts below 0.10 percent as a residual element carried over from the charge materials. Chromium is often added to improve hardness and strength of gray iron, and for this purpose the chromium level is raised to 0.20 to 0.35 percent. Beyond this range, it is necessary to add a graphitizer to avoid the formation of carbides and hard edges. Chromium improves the elevated temperature properties of gray iron.

One of the most widely used alloying elements for the purpose of increasing the strength is molybdenum. It is added in amounts of 0.20 to 0.75 percent, although the most common range is 0.35 to 0.55 percent. Best results are obtained when the phosphorus content is below 0.10 percent, since molybdenum forms a complex eutectic with phosphorus and thus reduces its alloying effect. Molybdenum is widely used for improving the elevated temperature properties of gray iron. Since the modulus of elasticity of molybdenum is quite high, molybdenum additions to gray iron increase its modulus of elasticity.

Vanadium has an effect on gray iron similar to molybdenum, but the concentration must be limited to less than 0.15 percent if carbides are to be avoided. Even in such small amounts, vanadium has a beneficial effect on the elevated temperature properties of gray iron.

The beneficial effect of relatively small additions of tin (less than 0.10 percent) on the stability of pearlite in gray iron has been reported by Davis et al^[11]. The results of extensive use of tin in automotive engines has been reported by Tache and Cage^[12]. Its use is particularly helpful in complex castings wherein some sections cool rather slowly through the Ar₃ temperature interval. It has been found that additions of up to 0.05 percent antimony have a similar effect. In larger amounts, these elements tend to reduce the toughness and impact strength of gray iron, and good supervision over their use is necessary.

Although most gray irons contain some titanium and the effect of titanium on the mechanical properties has been investigated many times, it is only recently that Sissener and Eriksson^[13] have reported the effect of titanium reduced from a titanium containing slag in an electric arc furnace. With titanium contents of 0.15 to 0.20 percent, the graphite flakes tend to occur as Type D graphite rather than predominantly Type A, which is generally considered desirable. They found that for irons with carbon equivalent of less than about 3.9 percent, the addition of titanium tends to lower tensile strength. but, for the higher carbon equivalent irons, tensile strength is improved. Increasing the titanium content of gray iron from about 0.05 to 0.14 percent through the use of a titanium bearing pig iron increased the strength of a hypereutectic iron in an ASTM Specification A 48 test bar A (7/8 in. diameter) from 22,000 to 34,000 psi. Further work is being done with titanium additions.

Normally. nitrogen is not considered as an alloying element and generally occurs in gray iron as a result of having been in the charge materials. Morrogh^[14] has reported that at higher nitrogen levels the graphite flakes become shorter and the strength of the iron is improved. Gray irons usually contain between 20 and 92 ppm (0.002 to 0.008 percent) nitrogen. If the nitrogen approaches or exceeds 100 ppm, unsoundness may be experienced if the titanium content is insufficient to combine with the nitrogen.