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To hit nails into things mostly. Shocking. Seriously: to hammer iron and steel without damaging it, as brass is softer.
When ever heat is applied there occur a change in grain structure.The best working temperature for steel is between 400 - 750 c. If steel is heated below 400c and then cooled it results a brittle zone. And above 750c heavy oxidation losses occur. If rate of cooling is fast it will result in fine grain structure and material will become hard. If rate of cooling is slow coarse grain structure is formed and material will be ductile.
Definitely not! Galvanized when heated will emit toxic fumes.
0.00000645in/in/deg F is the coefficient of expansion for steel. so if you had a 12" plate, that was heated up 30°f you would get "0.00000645 * 12 * 30 = 0.002322" (12" + 0.002322") would be the new length at the increased temperature.
The process of heat treatment in which a metal or alloy is heated to an appropriate temperature, held for a certain period of time, and then slowly cooled (usually as the furnace cools) is called annealing.The essence of annealing is to heat steel to austenitizing for pearlite transformation, and the annealed tissue is the nearly balanced one.Purpose of annealing:(1) Reduce the hardness of steel, improve the plasticity, and facilitate machining and cold deformation processing;(2) Uniform steel chemical composition and structure, refine grain, improve steel performance or prepare for quenching structure;(3) Eliminate internal stress and work hardening to prevent deformation and cracking.
When heated, steel becomes malleable, and can be hammered into shapes.
The bar will contract (get shorter) as it cools down, and expand (get longer) as it is heated up.
(After it has been heated.) It will harden. (At room temperature.) It will become brittle. (After it has been cooled .) It will become very brittle.
These are two different methods that are opposites. Surface hardening is used to stiffen a steel. Usually a steel is heated, a catalyst is applied to the surface and then the steel is quenched in an oil bath or waterbath, this hardens the surface of the steel. Annealing on the other hand, the steel is heated and then allowed to cool slowly. This softens the steel and allows it to be drawn or hammered to form a different shape.
steel is all three. when it is heated it melts into a liquid. if it is heated even more it evaporates into a gas. if gas steel is cooled it condenses into liquid steel and if liquid steel is colled even more it hardens into a solid again
Quenching steel involves rapidly cooling it to increase hardness, but this can make it too brittle. Tempering is a process where the hardened steel is heated to a specific temperature and then cooled slowly. This helps relieve internal stresses and makes the steel tougher and more ductile, balancing hardness with flexibility.
One can describe the process of case hardening of mild steel by adding carbon particles while tempering the steel. The outside of steel will become hard which form the case and inside the metal, it remains soft.
The steel would EXPAND
heated up to kindling temperature of the mild steel
Heat treating of high carbon steel to harden it is an instantaneous process. The steel is heated red hot, causing the formation of crystals of very hard type of Iron Carbide called "Martinsite". If cooled slowly, the Martensite reverts to iron and carbon again and the steel remains soft. But if cooled rapidly by plunging the red hot steel in water or oil, there is insufficient time for the Martinsite to break down to iron and carbon, and it remains as crystals of very hard Martinsite, imparting hardness to the steel.
One common method was known as Twist Steel. Thin steel rods were heated, and twisted together. They were reheated, and twisted around a metal rod. While on the rod they were heated a 3rd time, and hammered to weld the twisted strips together. After cooling, the rod was removed, leaving a hollow tube. One end would be fitted with a plug, the other left open to load powder and shot.
is the steel which breaks as it's heated to red hot