Martin (1992: 409-10):
Note that incongruence can flow against the nominalising semantic drift which characterises much abstract discourse in English; fields like personal computing for example contain a number of verbalised participants as technical terms: computerise, boot, format, log on, paginate, scroll, tab and so on.
 To be clear, nominalisation is a grammatical process; instances of other classes of grammatical form are transformed into nominals. The semantic drift of ideational metaphor is from logical to experiential meaning. Halliday & Matthiessen (1999: 269):
We can say therefore that grammatical metaphor is predominantly a ‘nominalising’ tendency. But if we look at it semantically we can see that it is a shift from the logical to the experiential: that is, making maximum use of the potential that the system has evolved for classifying experience, by turning all phenomena into the most classifiable form — or at least into a form that is more classifiable than that in which they have been congruently construed.
 Halliday & Matthiessen (1999: 286) explain the relation between grammatical metaphors and technical terms:
Almost all technical terms start out as grammatical metaphors; but they are grammatical metaphors which can no longer be unpacked. When a wording becomes technicalised, a new meaning has been construed — almost always, in our present-day construction of knowledge, a new thing (participating entity); and the junction with any more congruent agnates is (more or less quickly) dissolved.