How to hardensteel with a torch

Thermal cracking is a process that produces short straight chain paraffin from longer straight chains found in gas oils and other heavier crude oil fractions. The chemistry of thermal cracking involves free radicals that are reactive species with unpaired electrons but have a neutral electronic charge. It is the free radical chemistry that is responsible for producing gasoline with a relatively low octane number.

Tempering is a type of heat treatment for iron-carbon alloys. These alloys are more formally called steel. In general, the process for heat treating steel is accomplished by heating, rapid cooling, and reheating of the chosen material. When steel is cooled quickly, the atoms are “frozen” in an unstable position. The steel is very hard, but very brittle. By tempering steel, the atoms are allowed to rearrange into a more stable position. The hardness of steel is sacrificed for ductility (the materials ability to stretch or deform). The end result is a material with increased strength and toughness. Given these properties, it allows for the material to bend before fracturing and not break in a brittle manner, which can be beneficial in many structural applications. The steps performed are a very general outline to show the how some mechanical properties of steel increase with tempering. Different compositions and other steel alloys may require different heating times and temperatures as well as different quenching mediums depending on the use of the material. For this general procedure, allow 10-15 minutes for completion.

More steps to ensure proper safety may need to be taken if steps deviate from what is given in this general procedure. Fire will be coming from the blowtorch, so use extreme caution when heating the the steel. Finally, it is recommended that safety gloves be worn at all times, especially for more complex treatments.

How to hardensteel with oil

A Russian engineer named Vladimir Shukov introduced the first thermal cracking method in the Russian Empire in 1891. However, it was much later in 1912 that William Merriam Burton and Robert E. Humphreys designed a similar thermal cracking process which operated under temperature conditions of 700 to 750 °F and an absolute pressure of 90 psi. The advantage of the system they developed was that both the condenser and the boiler were continuously kept under pressure. A few years later in 1921, an employee at the Universal Oil Products Company, C.P. Dubbs, developed a more advanced technique which operated at higher temperatures of 750–860 °F. The design became known as the Dubbs process and was extensively used until the early 1940s.

How to hardenstainless steel

Make sure that the environment safe and clear from any potential hazards. Take the two steel rods and bend into a “U” shape. Be careful not to bend the rods too much and fracture the steel.

Modern day techniques of thermal processing include visbreaking and coking. Visbreaking is a mild fom of thermal cracking whereby the viscosity of the heavy crude oil residue is lowered significantly without affecting the boiling point range. Temperatures of about 950° F are used in the distillation column. Visbreaking mostly depends on temperature and time of the reaction. Coking is a severe form of thermal cracking that is used to convert heavy residuals into lighter more useful products and distillates. The most common coking techniques include delayed coking, fluid coking and flexi coking.

How to hardenmild steel at home

Take the second steel rod and temper it by reheating it with the torch for about 10 seconds. Do not temper the first steel rod! Quench again by placing it in bucket of water. This allows the atoms to “relax” and arrange themselves into a more stable position.

Attempt to straighten both rods to illustrate the difference in mechanical properties. The first rod (the rod that was not tempered, top photo), will be very brittle and will break since the atoms are not in a stable position. The second rod (the rod that was reheated or tempered, bottom photo), will bend but the “U” shape will remain. Since this rod was tempered and the atoms were allowed to “relax” to a stable position, the material becomes stronger and tougher.

When the rod becomes a deep orange in color, take the rod out of the flame and quickly dip it into the water inside the bucket, as shown in the photo (called quenching). Quenching drastically decreases the atoms’ motion, and can be illustrated as “freezing” the atoms in place. At this point, the atoms are in an unstable position.

Turn on the gas and light the blow torch. Be sure to have the blow torch pointed away from your body as shown. Make sure no one else is within three feet of the torch while it is lit. Have the fire extinguisher nearby in case of an emergency.

Place the curved part of the rod (the “U”) in the hottest part of the flame by holding the two ends of the steel rod. The hottest part of the flame is the small cone about halfway into the flame. Make sure you rotate the rod while it is being heated by the flame to make sure that it heats uniformly. The heat from the blowtorch “excites” the atoms into a more mobile state allowing them to rearrange.