nodular iron, obtains its special properties through the addition of magnesium into the alloy.
The presence of magnesium causes the graphite to form in a spheroid shape as opposed to the flakes of gray iron.
Composition control is very important in the manufacturing process. Small amounts of impurities such as sulfur and oxygen react with the magnesium, affecting the shape of the graphite molecules.
Different grades of ductile iron are formed by manipulating the microcrystalline structure around the graphite spheroid.
This is achieved through the casting process, or through heat treatment, as a downstream processing step.
Dislocations in materials refer to Line defect.
Line defects are lines along which whole rows of atoms in a solid are arranged anomalously.
The resulting irregularity in spacing is most severe along a line called the line of dislocation.
Line defects can weaken or strengthen solids.
The main alloying elements high speed steel in order of increasing proportion are
Induction hardening is a type of surface hardening in which a metal part is induction-heated and then quenched.
The quenched metal undergoes a martensitic transformation, increasing the hardness and brittleness of the part.
Which of the following is not the correct method of increasing fatigue limit?