Uluhlu lweqondo lobushushu obunqabileyo obusekwe kwityhubhu ezichanekileyo lunokwahlulwa lube lubushushu obuphantsi kunye nobushushu obuphezulu bobushushu obunobushushu obuphantsi.

Emva kokucaphuka brittleness echanekileyo ityhubhu ingxubevange intsimbi yacima martensite kuluhlu lobushushu 250 ~ 400 ℃ obushushu embrittlement intsimbi apho iqondo lobushushu brittle ductile inyuke kakhulu.Yenzeka ikakhulu kwintsimbi yensimbi yealloy kunye ne-low-alloy high power precision tubes.Sele ityhubhu esele i-brittle fracture echanekileyo kukuqhekeka okuphakathi kwegranular okanye i-quasi-cleavage kunye ne-intergranular fracture exutyiweyo.Cause tempering brittleness, ngokubanzi kuqwalaselwa: (1) kunye nesamente ngexesha tempering kwi sheet kwimida yokuqala austenite okuziinkozo, ebangela okuziinkozo embrittlement emdeni zihlobene ngokusondeleyo.(2) izinto zokungacoceki ezifana ne-phosphorus kwi-austenite grain boundary segregation sesinye sezizathu ezibangela ukuba buthathaka.I-Phosphorus engaphantsi kwe-0.005% yeetyhubhu ezichanekileyo zokucoceka okuphezulu azivelisi ukuvutha kobushushu obuphantsi.I-Phosphorus yenzeka kwimida yengqolowa ye-austenite xa ulwahlulo lokufudumala komlilo emva kokucima lugcinwe.Iphosphorus kulwahlulo lomda weenkozo eziziinkozo ze-austenite kunye nesamente ngexesha lobushushu kwimida yangaphambili yeenkozo ze-austenite, ezi zinto zimbini zibangele ukuqhekeka kwe-intergranular brittle fracture, kube negalelo kubushushu oburhabaxa.

Iziqalelo zokudityaniswa kwetyhubhu echanekileyo zinempembelelo enkulu kubushushu obuphantsi obunobushushu obuphantsi.I-Chromium kunye ne-manganese zikhuthaza ucalucalulo lwezinto ezingacocekanga ezifana ne-phosphorus kwimida ye-austenite grain, ngaloo ndlela inegalelo ekucaphukiseni i-brittleness, i-tungsten kunye ne-vanadium ayinasiphumo, i-molybdenum idodobalisa ukuqina kokutshintsha kweqondo lobushushu elibi leetyhubhu ezichanekileyo, kodwa akwanelanga ukuthintela ukucaphuka. .Xa i-silicon inokuthi ibeke elinye ixesha imvula ye-cementite epholileyo, eyenza ukunyuka kwamaqondo obushushu, kunokwenzeka ukuphucula iityhubhu ezichanekileyo zobushushu bobushushu buyenzeke.