What is the difference between hardening and tempering steel?

As the names imply, hardening makes the metal more rigid but more brittle, and tempering (from “temperate”, moderate), forgoes some hardness for increased toughness. It is done to relieve internal stresses, decrease brittleness, improve ductility and toughness.

What’s the difference between quench and temper?

Quenching is when you cool a solution treated steel quickly enough that carbides do not precipitate out of solution in a stable way. Tempering is when you take that quenched steel and heat it enough to begin precipitating the carbides but not enough to put everything back into solution.

Is there any difference between quenching and hardening?

Hardened materials are usually tempered or stress relieved to improve their dimensional stability and toughness. Steel parts often require a heat treatment to obtain improved mechanical properties, such as increasing increase hardness or strength. Quenching “freezes” the microstructure, inducing stresses.

Why is quenching done?

In metallurgy, quenching is most commonly used to harden steel by inducing a martensite transformation, where the steel must be rapidly cooled through its eutectoid point, the temperature at which austenite becomes unstable. This allows quenching to start at a lower temperature, making the process much easier.

Which of the following is a case hardening process?

To achieve these different properties, two general processes are used: 1) The chemical composition of the surface is altered, prior to or after quenching and tempering; the processes used include carburizing, nitriding, cyaniding, and carbonitriding; and 2) Only the surface layer is hardened by the heating and …

Can you quench in vegetable oil?

There are many food-grade quenching oil options available to use for blacksmithing. Among these options are vegetable, peanut, and avocado oil. Some commonly used vegetable oils are canola, olive, and palm kernel oil.

Why do you quench a blade in oil?

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.

How do you heat quench oil?

A heated bar of steel works fine for warming the oil. I have a 1/2″ rod with a 6″ piece of 1″ round welded on one end. I stick it in the forge and bring it to dull red, quench and stir, check the temp, repeat. When the oil is 130F it is ready.

Which metal is required to harden the steel?

Chromium

How do you harden a knife edge?

You can think of hardening a knife as a three part process:

You heat the blade up, red hot (change it to austenite)
Cool it down quickly (quenching: changing the austenite to martensite)
Then heat it up again, but not as much as the first time (tempering: toughening the martensite)