Txias-cov raj yog cov raj hlau uas tsim los siv cov txheej txheem kos duab txias-. Cov txheej txheem tsim khoom no tsis tso siab rau siab - kub cua sov, tab sis yog plastically deforms cov hlau raj ntawm chav tsev kub. Cov txheej txheem no txhim kho qhov tseeb qhov tseeb, qhov chaw tiav, thiab cov khoom siv kho tshuab ntawm lub raj steel, thiab yog siv dav hauv kev tsim khoom, kev lag luam tsheb, thiab hydraulic systems.
Lub hauv paus ntsiab lus tseem ceeb ntawm cov khaub thuas- cov raj yog siv cov quab yuam sab nraud los ua kom lub cev tsis zoo ntawm lub raj hlau hauv qhov tuag. Thaum lub sij hawm ua, ib kawg ntawm cov hlau raj dawb paug yog yuam kom rub los ntawm qhov tuag orifice. Lub zog tensile kov yeej cov hlau tsis kam rau deformation, txo nws cov ntoo khaub lig-section thiab nce nws qhov ntev. Thaum lub sijhawm txheej txheem no, kev sib txhuam hnyav ntawm lub raj thiab cov phab ntsa sab hauv ntawm cov tuag yuam cov hlau nplej kom rov zoo raws li cov kev taw qhia ntawm stretching, uas ua rau lub microstructure denser. Vim tias tag nrho cov txheej txheem siv nyob rau hauv chav tsev kub, cov hlau hardness thiab lub zog nce vim ua hauj lwm hardening, thaum nws ductility txo raws li.
Tus yuam sij rau qhov txias - txheej txheem kos duab yog nyob rau hauv kev tsim tuag thiab kev tswj nruj. Cov tuag feem ntau yog ua los ntawm cov khoom siv siab- hardness, thiab cov duab ntawm nws lub qhov sab hauv txiav txim siab qhov tseeb qhov tseeb ntawm lub raj tiav. Kev kos duab quab yuam yuav tsum raug xam kom meej kom ntseeg tau tias cov yas deformation txaus ntawm cov hlau thaum tsis txhob tawg vim muaj zog ntau dhau. Txhawm rau txo qis kev sib txhuam, cov roj nplua nyeem feem ntau siv thaum lub sijhawm ua haujlwm, thiab ntau qhov kev kos duab dhau los yuav raug ua haujlwm kom maj mam ua tiav lub hom phiaj qhov ntev.
Piv nrog rau cov kub-kub dov, txias- cov raj tau kos muaj qhov raug siab dua qhov tseeb thiab qhov chaw smoother, tab sis lawv cov khoom siv tau qis dua thiab lawv cov nqi siab dua. Cov txheej txheem kev kos duab txias ua kom zoo dua qhov kev ntxhov siab seem nyob hauv cov khoom siv hlau, uas ua rau cov khoom kawg nthuav tawm zoo heev compressive, hnav, thiab qaug zog. Cov txheej txheem no yog tshwj xeeb tshaj yog haum rau cov ntawv thov uas yuav tsum tau stringent tube precision thiab mechanical zog, thiab yog ib tug indispensable technical cuab tam nyob rau hauv niaj hnub metalworking.
