Umuyoboro w'icyuma udafite icyerekezo ni ubwoko bw'icyuma kidafite icyuma, kandi imikorere yacyo irarenze cyane iy'icyuma gisanzwe kidafite icyuma.Umuyoboro w'icyuma udafite uburinganire urimo ibintu nka silicon, manganese, chromium, nikel, molybdenum, tungsten, vanadium, titanium, niobium, zirconium, cobalt, aluminium, umuringa, boron, isi idasanzwe, n'ibindi.