Question: What Oil Is Good For Quenching?

Where is case hardening used?

Typical uses are for the shackle of a lock, where the outer layer is hardened to be file resistant, and mechanical gears, where hard gear mesh surfaces are needed to maintain a long service life while toughness is required to maintain durability and resistance to catastrophic failure..

What oil is used for quenching?

The two most common food grade oils used in this process are peanut and canola oil. Both of these oils have high flash points which is good for the quenching process. You will need to preheat these oils to slightly higher temperatures when compared to commercial quenching oils (120 – 130 degrees Fahrenheit).

How do you harden steel with motor oil?

One way to do this is to make the steel red-hot, then plunge it into motor oil. The carbon in the motor oil bonds with the top layer of red-hot steel molecules and forms a tough outer covering on the steel. One last step is necessary, however, before your hardened steel is ready to work with.

Does oil quenching prevent rust?

As H2O is unable to penetrate the metal, the rusting process doesn’t start. As well as tangible water, oil also repels the water that’s present in oxygen. This means that even when metal objects aren’t coming into direct contact with water, a slick of oil can still work wonders when it comes to preventing rust.

How hot should quenching oil be?

Quenching into oil above 212°F (100°C) has traditionally been referred to as “hot oil” quenching. Oil temperatures in the 195°F – 450°F (90°C – 230°C) range have been used with both ends of the spectrum normally reserved for special applications.

What does dipping hot metal in oil do?

In the initial vapor blanket stage, the hot metal is submerged into the quenching oil. The temperature difference between the hot metal and the cool liquid causes the oil to vaporize. Cooling of the metal is impeded by the vapors that surround the metal, like a blanket, and prevent heat transfer.

Why is quenching in oil better than water?

Water-quenched steels will generally be harder than oil-quenched steels. This is mainly because the thermal conductivity of water is higher than the thermal conductivity of most oils (that I know); consequently, the rates of cooling will be less rapid (or lower) in oils compared with water.

Should I quench in water or oil?

Water quenching is a rapid cooling, where water as a qenching medium extracts heat much faster. While oil as a medium will extract heat much slower, hence rate of cooling will be slower than water.

Can you oil quench stainless steel?

Full hardness can be achieved through air-cooling at the austenitising temperature, but hardening larger sections may sometimes require oil quenching. Hardened components must be tempered immediately after cooling at room temperature, particularly if oil quenching has been used to prevent cracking.

What liquid is used to quench steel?

Water is an effective medium when the goal is to have the steel to reach maximum hardness. However, using water can lead to metal cracking or becoming distorted. If extreme hardness isn’t necessary, mineral oil, whale oil, or cottonseed oil may be used in the quenching process instead.

What happens during quenching?

Quenching involves the rapid cooling of a metal to adjust the mechanical properties of its original state. To perform the quenching process, a metal is heated to a temperature greater than that of normal conditions, typically somewhere above its recrystallization temperature but below its melting temperature.

What is quenching oil made of?

Parts made of low-carbon steel and low-hardenability alloys quench better in fast oils. Hot oils are kept at much higher temperatures and are used to ensure that a part’s core temperature and surface temperature do not vary too greatly during a quench. This controls distortion and reduces the risk of cracking.

Why do blacksmiths quench in oil?

When hardness can be sacrificed, mineral oils are often used. These oil-based fluids often oxidize and form a sludge during quenching, which consequently lowers the efficiency of the process. … Often, after quenching, an iron or steel alloy will be excessively hard and brittle due to an overabundance of martensite.

What oil do you use to heat treat a knife?

Quenching oil is very sophisticated in design and application. If you can’t afford it, use low viscosity motor oil or even canola, vegetable or peanut oil. It won’t be perfect but, it will work. Veteran knife makers will tell you to use dedicated heat treat quench oil to get better results.

What is the difference between quenching and tempering?

The process of quenching or quench hardening involves heating the material and then rapidly cooling it to set the components into place as quickly as possible. … Tempering is achieved by heating the quenched material to below the critical point for a set period of time, then allowing it to cool in still air.

Why does quenching increase hardness?

Heating the material above the critical temperature causes carbon and the other elements to go into solid solution. Quenching “freezes” the microstructure, inducing stresses. Parts are subsequently tempered to transform the microstructure, achieve the appropriate hardness and eliminate the stresses.

Can you use used motor oil for quenching?

Yeah, use motor oil if you have it. A medium hydraulic oil or a vegetable oil might be better but any oil will do. It’s the cooling rate that’s important in a quenchant and not much else.

Can you use vegetable oil for quenching?

Oil is a third traditional quenching agent, suitable for high-speed steels and oil-hardened steels, and in fact for any steel for which the required degree of hardness is achievable. Oil has a slower rate of cooling compared to either water or brine, but faster than air, making it an intermediate quench.

What kind of oil do Bladesmiths use to quench?

Motor Oils1) Motor Oils Motor oils are a common type of quenching oil used in both blacksmithing and bladesmithing applications. New and used motor oils can be used for quenching and are both widely available.

Which quenching medium produces the slowest quench?

Liquid cooling starts when the surface temperature of the metal reaches the boiling point of the liquid so that vapor is no longer formed. This is the slowest stage of cooling.