What is Quench: Definition and 12 Discussions

In materials science, quenching is the rapid cooling of a workpiece in water, oil or air to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, such as phase transformations, from occurring. It does this by reducing the window of time during which these undesired reactions are both thermodynamically favorable, and kinetically accessible; for instance, quenching can reduce the crystal grain size of both metallic and plastic materials, increasing their hardness.
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. In steel alloyed with metals such as nickel and manganese, the eutectoid temperature becomes much lower, but the kinetic barriers to phase transformation remain the same. This allows quenching to start at a lower temperature, making the process much easier. High-speed steel also has added tungsten, which serves to raise kinetic barriers, which among other effects gives material properties (hardness and abrasion resistance) as though the workpiece had been cooled more rapidly than it really has. Even cooling such alloys slowly in air has most of the desired effects of quenching; high-speed steel weakens much less from heat cycling due to high-speed cutting.Extremely rapid cooling can prevent the formation of all crystal structure, resulting in amorphous metal or "metallic glass".

View More On Wikipedia.org
  1. E

    The most boring quantum quench (looking for a textbook/paper)

    Hi, usually, when we talk about quantum quench dynamics we assume situation when Hamiltonian of a system has a sudden change from ##H_0## to ##H_1##. System was initially in the ground state (or more generally - eigenstate) of ##H_0##. The interesting dynamics appears when the commutator...
  2. alphaj

    Chemistry ORGO: What does it mean when a molecule is 'quenched?'

    Homework Statement n/a Homework Equations n/a The Attempt at a Solution n/a Just a question. I keep seeing that in SN2 reactions, sometimes a molecule is quenched by H2O or H3O. I've seen it turn an O- into an OH and also a heteroatom into an H. What exactly is going on here?
  3. B

    I How to calculate Miits (quench integral)?

    How to find the value of miits integral for calculations of the propagation of normal zonei in superconductors?
  4. L

    Cooling Steel Die for Contact Cooling of Aluminium - Advice Needed

    Hi, I am designing a system to cool aluminium through contact cooling. I have a steel die with 9x 20mm diameter cooling chambers. Water is pumped through the chambers which cools the steel die and hopefully the aluminium sitting on top of it. I am looking to find the temperature of the...
  5. E

    A Is my solution of time-dependent Schrodinger equation right?

    The problem looks very simple. We have a time-dependent Hamiltonian: $$H(t) = B(t)H_0$$, where ##B(t)## is a numerical function, and matrix ##H_0## is time-indpendent. Let us consider: $$B(t) = \begin{cases} 1,&\text{for $0\leq t\leq t_0$}\\ A,&\text{for $t>t_0$.} \end{cases}$$ Also, let us...
  6. L

    Jominy Quench test of different steel alloy samples

    Hi, So the other day we performed the Jominy quench test on 4 different steel samples. We followed the standard procedure (heating to austenite, then quenching it at one end, then polishing and etch it for micrograph examination) Now I need to write about the expected phases in each steel sample...
  7. H

    Quench spreading on multiple coils superconducting magnet

    The multiple coils superconducting maget is uaually quench protected by bypass diodes. The heat spreading model is mentioned on textbook for coil to coil quench spreading. But the heat spreading is not fast enough for magnet quench protection. Because the theoretical quench protection...
  8. A

    What is Quench Parameter? & Where Does it Apply?

    Could anybody tell me what is so called Quench Parameter ? And where is that parameter applys into? Thanks a lot! :smile:
  9. Y

    About superconduct MRI quench protection

    Hi,I study protection of superconducting coils.I adopt heaters to protect coils.The circuit is in attachment. There are 6 coils,so I use 6 quench heaters.I want to know how I choose the heaters? It must do the Quench Heater Simulation for protection of superconducting coils before...
  10. N

    What is Quench Management for Magnetism?

    Hi, Can someone please explain what Quench Management is particularly when applied to magnetism. Thanks Regards neorich
  11. Q

    ASTM A182 F22 Quench Properties

    Greetings! First time poster here. I'd appreciate whatever help anyone can provide. I have some pieces of F22 that were quenched and tempered. My customer needs to know how deep the quench properties extend, as he intends to machine off some of the O.D. Critical Diameter analysis is not...
  12. K

    Refinery Expertise: Enhancing Propane/Ethane Streams and Quench Processes

    Does anyone know how to get more ethene out of a propane/ethane stream? I know you can use a higher temperature, but can you do something with the steam ratio or pressure too? Also: After the reaction, we use a quench with water injection. Why should we do a compression step first before...