The best stuff is compacted graphite iron (CGI), which falls between gray and nodular iron in strength and stiffness while providing greater resistance to fatigue cracks. … Since CGI is stronger and tougher, block walls can be thinner and main bearing saddles narrower, trimming overall engine length and weight.
What is GCI cast iron?
Compacted graphite iron (CGI), also known as vermicular graphite iron (GJV, VG, JV or GGV from the German: “Gusseisen mit Vermiculargraphit”) especially in non-English speaking countries, is a metal which is gaining popularity in applications that require either greater strength, or lower weight than cast iron.
How strong is compacted graphite iron?
While not quite as strong as ductile iron, CGI is 75 percent stronger and up to 75 percent stiffer than gray iron. The thermal and damping characteristics of CGI are midway between ductile and gray iron.
Why do cast iron engines block?
Cast iron is used for engine blocks because of its carbon content. It has more carbon that steel, high speed tool steel, and can be harder than some titanium alloys. The carbon content in steel is what makes it hard.
What is SGI material?
SG Iron is also known as Ductile Cast Iron, Nodular Cast Iron, Spheroidal Graphite Iron and Spherulitic Cast Iron. This grade of Iron was developed over 60 years ago and in the USA. … The main characteristic of this material is the structure of the graphite.
Which is better cast iron or ductile iron?
Ductile iron has excellent corrosion resistance, tensile strength, and yield strength. Unlike cast iron, ductile iron does not break when it is bent, so it is more suited for high demand applications. … Ductile iron is typically more expensive than cast iron due to its more complicated chemical makeup.
What is difference between cast iron and SG iron?
The difference between traditional cast iron and modern-day ductile iron is the shape of the graphite. While cast iron has small flakes of graphite, ductile iron contains spherical graphite nodules. Because of the spherical shape of the graphite, ductile iron is often called spheroidal iron or nodular cast iron.
What is GREY cast iron used for?
It is the most common cast iron and the most widely used cast material based on weight. It is used for housings where the stiffness of the component is more important than its tensile strength, such as internal combustion engine cylinder blocks, pump housings, valve bodies, electrical boxes, and decorative castings.
What is white iron?
Definition of white iron
1 : iron in thin sheets coated with tin : tinplate. 2 : a hard silvery-white pig iron or cast iron having its carbon content almost entirely in combined form.
Why is wrought iron called?
The term “wrought iron” comes from the past tense form of the verb to work. Throughout time, many historic forms of the English language have fallen of use and after a long period of time the word “wrought” became replaced by “worked.” So, in a literal sense, the term “wrought iron” means “worked iron.”
Is a cast iron block better than aluminum?
Because iron is more rigid than aluminum, it won’t deflect and distort as much under high cylinder pressures. … Modern aluminum blocks are pretty strong, but a properly built iron block is still ultimately going to be stronger, and that strength offers some benefits that might be less obvious.
What is the best material for an engine block?
Engine blocks are normally cast from either a cast iron or an aluminium alloy. The aluminium block is much lighter in weight, and has better heat transfer to the coolant, but iron blocks retain some advantages such as durability and better clearances from heat expansion.
How can I make my engine block stronger?
Some factory blocks incorporate “girdles” which significantly increase the stiffness of the bottom end of the block. On blocks not using a factory girdle, sometimes an aftermarket girdle or aftermarket steel main caps can be installed to strengthen the block.
Is ductile iron the same as carbon steel?
Ductile iron has higher strength, better ductility, heat-resistance and toughness than grey iron, so it has a wider application, in some cases, ductile iron can replace carbon steel. Carbon steel has higher strength, very high ductility, and toughness, even better than ductile iron.
Is cast iron brittle?
Cast iron is harder, more brittle, and less malleable than wrought iron. It cannot be bent, stretched, or hammered into shape, since its weak tensile strength means that it will fracture before it bends or distorts.
What is nodular steel?
Nodular cast iron is a material that has found a increasing number of applications in the automotive industry during the last decade. It has a static strength comparable to cast steels and a greater fatigue strength and ductility than grey irons.