Fill the clear jar halfway with cold water. Place the jar freezer for 15 minutes.
Al, Si, Mg, Pb trace no greater than 0. The ability to be hardened varies with the carbon and alloy content of steel. The higher the carbon content the harder the steel can become. Low carbon steel has very low hardenability and wrought iron which has no carbon is unhardenable.
To harden steel it is heated above the "transformation point", a low red or just above where the steel becomes non-magnetic. Then it is quenched in brine, water, oil or even air. Afterwards it is tempered by reheating. This reduces the brittleness of the steel a lot and the hardness just a little.
The quenchant depends on the type of steel.
In general quenching in a more sever quenchant than necessary can cause cracks in the steel. Overheating prior to the quench can do the same. In general hard parts are always more brittle than soft parts.
Using parts that are too hard can be dangerous. On machines this can mean parts that may explode or shatter. I left a bunch of variables open above.
This is the nature of the game. The starting place is to know what kind of steel you are working with. IF you don't know what kind of steel you are using then you have to become your own metallurgist and do some detective work.
This requires lots of trial and error and attention to detail, plus a lot of knowledge. There is no simple formula or magic bullet. If you start working with a variety of steels you will also need the ASM Metal Reference Book as it has more complete listings of numerous alloys.
You can hear the difference in sound as the piece becomes work hardened and needs to be heated again. Low carbon steel will harden slightly but not to the degree of spring or tool steels. The parameters of the heattreating sequence is determined by the type of steel.
Once hardened, the part must be tempered. Tempering is the reheating of the part to a temperature well below the hardening temperature to reduce the hardness and increase the toughness.
On very hard critical parts double tempering doing more than once is recommended. Tempering helps reduce hardening stresses and double tempering is cheap insurance.
Mineral oil is the least toxic. For something the size of a power hammer die you will want several gallons. Oil is lower density than water, has lower thermal conductivity and flashes rather than evaporate if over heated.
Therefore it takes quite a bit more oil to quench a part than water.
If you quench with too little water it just boils off. If you have too little oil it goes up in explosive smoke that is often ignited by the hot steel. If you must use automotive oils use ATF.
It has less possibly toxic additives than regular oils.See also tabulated values of specific heat of Gases, Food and foodstuff, Common liquids and fluids, Common solids and other Common substances as well as values of molar heat capacity of common organic substances and inorganic substances.
See also tabulated values of specific heat of Gases, Food and foodstuff, Common liquids and fluids, Common solids and other Common substances as well as values of molar heat capacity of common organic substances and inorganic substances.
In this science experiment, observe convection currents forming and learn about how heat energy moves in liquids from hot to cooler areas through convection. CHEM Lab Guide Page 1 Experiment 9 Experiment 9 Specific Heat Capacities of Metals The purpose of this experiment is to identify two unknown metal samples based.
Stainless steels are iron-base alloys containing at least 11 wt.% Chromium. They typcially contain less than 30 wt.% Cr and more than 50wt.% Fe. Stainless steels obtain their stainless characteristics because of the formation of an invisible and adherent chromium-rich oxide surface film.
HIGH-TEMPERATURE CHARACTERISTICS OF STAINLESS STEELS NiDI Distributed by NICKEL DEVELOPMENT INSTITUTE For a given type of steel at a specific thickness, the expected service life The strengthening of stainless steels by cold working or heat treatment can be.