A steel with a higher than usual content of sulfur and phosphorus intended for the fabrication of parts for high-speed automatic and semiautomatic machine tools. Free-cutting steel is produced in the form of rods, and it contains 0.08–0.45 percent carbon, 0.15–0.35 percent silicon, 0.6–1.55 percent manganese, 0.08–0.30 percent sulfur, and 0.05–0.16 percent phosphorus. The high…
Stainless Steel is defined as that steel which when correctly heat treated and finished, resists oxidation and corrosive attack from most-corrosive media. The different types of stainless steels are as follows: 1. Martensitic stainless steel. The chromium steels containing 12 to 14% chromium and 0.12 to 0.35% carbon is called martensitic stainless steel, as they possess…
Allotropic Forms of Pure Iron – we know that pure substances may exist in more than one crystalline form. Each such crystalline form is stable over more or less well defined limits of temperature and pressure. This is known as allotropy or polymorphism. The pure iron exists in the following three allotropic forms: (a) Alpha…
The various metals for producing nuclear energy are used as raw materials for moderators, reflectors, fuel elements, fuel canning materials, control elements and pressure vessel materials. The important metals used for nuclear energy are uranium, thorium, plutonium, zirconium, beryllium and niobium.
What are high temperature alloys? The high temperature alloys are those alloys which can withstand temperature in excess of 1100 degree celcius. These alloys are used in components of nuclear plants, jet and rocket engines. Some of the high temperature alloys are as follows: 1. Incoloy. It is a nickel base alloy. It consists of 42% nickel, 13%…
The cast iron is obtained by remelting pig iron with coke and lime stone in a furnace known as cupola. It is primarily an alloy of iron and carbon. The carbon contents in cast iron varies from 1.7 to 4.5%. It may be present either as free carbon (or graphite) or combined carbon (or cementite). Since the…
It is a science that deals with the association among the structure and the properties of the materials. Properties of materials: Properties of the materials are divided in to six categories. They are Decorative Electrical Magnetic Mechanical Optical Thermal Every material possesses a structure, relevant properties. They depend upon the giving out and govern the…
What is the effect of grain size on mechanical properties of metals? All solid metals are crystalline and the crystals or grains are made up of several atoms. The grain size has an important effect on the mechanical properties of a metal. The size of the grains depends upon a number of factors, but the…
An alloy steel may be defined as a steel to which elements other than carbon are added in sufficient amount to produce an improvement in properties. The chief alloying elements used in steel are as follows: I. Nickel. The steels containing 2 to 5% nickel improves tensile strength, raises elastic limit, imparts hardness, toughness and reduces…
A modified iron-carbon diagram is shown in Fig. 13.2. The point A (1539° C) on the diagram is the melting point of pure iron. The point E shows the solubility limit of carbon in gamma iron at 1130° C (1.7%). The iron carbon alloys containing upto 1.7% carbon are called steels and those containing over 1.7% carbon…