BS EN ISO 4885:2015 pdf download

BS EN ISO 4885:2015 pdf download.Draft BS EN ISO 4885 Ferrous products – Heat treatments – Vocabulary.
3.45
controlled rolling
Rolling process where rolbng temperature and reduction are controlled to achieve enhanced mechanical properties. e.g. normahzing rolling, thermornechanical rolling.
NOTE Controlled roling Is used tow example for fine grain ferritic steels and br dual phase steel for obtarning line grain Structure.
3.46
cooling
reduction 01 the temperature of a ferrous product. The cooling process may be carried out in one or more steps
NOTE The medium in hich cooling tii.es place should be specified, br example in furnace, ale. Oil, waler (see also ienching).
3.47
cooling condItions
conditions (nature and temperature of the medium, relative movements, agitation. etc.) under which the cooling of the ferrous product lakes place
3.48
cooling function
successive variations in the temperature at one point in the ferrous product considered, as a function of time Iron, the con,rnencernent of cooling to the end of this operation This function could be shown as a graph or could be written in a mathematical form
3.49
cooling rate
variation In temperature as a function of lime during cooling
NOTE A distinction is made between
an instantaneous rate corresponding to a specified temperature. and
– an average rate over a defined intewval of temperature.
3.50
cooling time
interval of time separating two characteristic temperatures of the cooling function
NOTE It ls always necessary to specify precisely what the temperatures are.
3.51
core refining
double quench-hardening of carburized workpieoes to 9et a fine grain and a homogenous microstructure in core according to Figure 1 d.
NOTE The fir4 quencti-hardenwig should be clone from a temperature according to the carbon content of the not carburized core and the second accorcng to the carbunzed surlace.
3.52
critical cooling lapse
cooling lapse in according to avoid transformation in undesired microstructure
NOTE This ternl should be complnted by an inccalion of the transformation considered, e.g. maiiensillc. bainitic, etc.
3.53
critical cooling rate
cooling rate corresponding to the cittical cooling Lapse
3.54
critical diameter
diameter ( a bar of length  3 d having a structure of 50 % marlensite at its centre after quenching under given conditions
3.55
critical points
temperatures of transformauons from one or more mecrostructures to other mecrostructures
NOTE The term shall be completed by indication of the kind of the microsfruclure. e.g. critoai point of the martensAlic stage. pearlilic stage etc.
3.56
decarburl.zatton
doplebon of carbon from the surface layer of a workpiece
NOTE This depletion may be either partial (partial decarburization) or nominally complete (complete decaiburtzation). The sum of the two types of decarburtzation (partial and compiete( is termed total decarbunzation. (See ISO 3887,)
3.57
decarburlzing
thermochen,ical treatment intended to produce decarburization of a worlcpiece
3.58
decomposition of austenite
decomposition into ferrite and pearlite or ferrite and cementite with decreasing temperature
3.59
delta iron
stable state of pure iron between 1.392 °C and its melting point
NOTE I Its uystalline struchxe is body-centred aibic. dentical to that of alpha jon. NOTE 2 ills pararnagnetlc.
3.60
depth of carburizing (nltrlding) I carburLzing (nltriding) depth
distance between the surface of a worlpiece and a specified limit characterizing the thickness of the layer enriched in carbon (nitrogen), wti,ch means effective case depth
3.61
depth of decarburization I decarburization depth
distance between the surface of a workpiece and a limit characterizing the thickness of the layer depleted in carbon
NOTE This limit varies according to the type of decarburization and can be defined by reference to a structLKal slate. a level of hardness or the carbon content of the unaflered base metal (see ISO 3887), or any other specified carbon content.
3.62
depth of hardening
distance between the surface of a wor1ipiece and a limit characterizing the penetration of quench hardening
NOTE This limit may be defined starting from a structural state or a level of hardness.