By heating them to redness and then quenching them in cold water.
The peculiarity of these steels is that no quenching or tempering is required.
However this may be, very soon after man began to practise hot-forging he would inevitably learn that sudden cooling, by quenching in water, made a large proportion of his metal, his steel, extremely hard and brittle, because he would certainly try by this very quenching to avoid the inconvenience of having the hot metal about.
Is cooled suddenly by quenching in water, in which case the carbon present seems to act as a brake to retard the change; or completely, by the presence of a large quantity of manganese, nickel, tungsten or molybdenum, which in effect sink the lower boundary GHSa of region 4 to below the atmospheric temperature.
Austenite may contain carbon in any proportion up to about 2.2 It is non-magnetic, and, when preserved in the cold either by quenching or by the presence of manganese, nickel, &c., it has a very remarkable combination of great malleability with very marked hardness, though it is less hard than common carbon steel is when hardened, and probably less hard than martensite.
Again, (3-iron may be preserved incompletely as in the " hardening of steel," which consists in heating the steel into the austenite state of region 4, and then cooling it so rapidly, by quenching it in cold water, that, for lack of the time needed for the completion of the change from austenite into ferrite and cementite, much of the iron is caught in transit in the (3 state.
I, and then quenching it, usually in cold water, so as to cool it very suddenly, and thus to deny the time which the complete transformation of the austenite into ferrite and cementite requires, and thereby to catch much of the iron in transit in the hard brittle state.
After this carburizing these objects are usually hardened by quenching in cold water (see § 28).
Their attacks on infant baptism seemed to him not altogether irrational, and in regard to their claim to personal inspiration he said "Luther alone can decide; on the one hand let us beware of quenching the Spirit of God, and on the other of being led astray by the spirit of Satan."
801 and 802) and on the 23rd of August there was a sacrifice to him together with Ops Opifera and the Nymphae, which suggests the need of water in quenching the flames.
This quenching of the light of the world is symbolized at the service of Tenebrae in Holy Week by the placing on a stand before the altar of thirteen lighted tapers arranged pyramidally, the rest of the church being in darkness.