Ukunyangwa kokushisa kweekhemikhali kweentsimbi zetsimbi

Ukunyangwa kobushushu bekhemikhali yeentsimbi zentsimbi kubhekiselele ekubekeni i-castings kwindawo esebenzayo kwiqondo lobushushu elithile lokugcinwa kobushushu, ukuze enye okanye izinto ezininzi zeekhemikhali zingene kumphezulu. Ukunyangwa kokushisa kweekhemikhali kunokutshintsha ukubunjwa kweekhemikhali, isakhiwo se-metallographic kunye neempawu zomatshini zobuso bokuphosa. Iinkqubo zokunyanga ukushisa kweekhemikhali eziqhelekileyo ezisetyenziswayo ziquka i-carburizing, i-nitriding, i-carbonitriding, i-boronizing kunye ne-metalizing. Xa usenza unyango lobushushu beekhemikhali kwi-castings, imilo, ubungakanani, imeko yomgangatho, kunye nokuphathwa kobushushu obuphezulu bokuphosa kufuneka kuthathelwe ingqalelo ngokubanzi.

 

1. Carburizing

I-Carburizing ibhekisa kubushushu kunye nokugquma ukuphosa kwindawo yokungcwaba, kwaye emva koko kungene iiathom zekhabhoni kumphezulu. Injongo ephambili ye-carburizing kukunyusa umxholo wekhabhoni phezu kwendawo yokuphosa, ngelixa usenza i-gradient ye-carbon content gradient kwi-casting. Umxholo wekhabhoni wensimbi ye-carburizing ngokuqhelekileyo ngu-0.1% -0.25% ukuqinisekisa ukuba i-core of casting inobunzima obaneleyo kunye namandla.

Ukuqina komphezulu womaleko we-carburized ngokuqhelekileyo yi-56HRC-63HRC. Isakhiwo se-metallographic somgangatho we-carburized inaliti entle ye-martensite + inani elincinci le-austenite egciniweyo kunye ne-carbides yegranular esasazwe ngokufanayo. I-Carbides yenethiwekhi ayivumelekanga, kwaye isahlulo somthamo we-austenite egciniweyo ngokubanzi ayidluli kwi-15% -20%.

Ubunzima obungundoqo bokuphosa emva kokungcwatywa kwe-carburizing ngokubanzi yi-30HRC-45HRC. Ubume be-metallographic engundoqo kufuneka ibe yi-low-carbon martensite okanye i-bainite ephantsi. Akuvumelekanga ukuba ne-ferrite enkulu okanye enamanzi ecaleni komda weenkozo.

Kwimveliso yokwenyani, kukho iindlela ezintathu eziqhelekileyo zokungcwatywa kwe-carburizing: i-carburizing eqinileyo, i-liquid carburizing kunye ne-gas carburizing.

2. I-Nitriding

I-Nitriding ibhekiselele kwinkqubo yonyango lobushushu elifaka iiathom zenitrogen kumphezulu wokugalela. I-Nitriding ngokuqhelekileyo yenziwa ngaphantsi kobushushu be-Ac1, kwaye injongo yayo ephambili kukuphucula ukuqina, ukumelana nokunxiba, amandla okudinwa, ukuxhathisa ukubanjwa kunye nokuxhathisa ukudumba kwe-atmospheric yendawo yokuphosa. Ukufakwa kwe-nitriding yeentsimbi zentsimbi ngokuqhelekileyo kuqhutyelwa kwi-480 ° C-580 ° C. Ukusaswa okuqulathe ialuminiyam, ichromium, ititanium, imolybdenum, kunye netungsten, njengentsimbi ephantsi yealloyi, intsimbi engatyiwayo, kunye nentsimbi yokungunda eshushu, zifanelekile kwinitriding.

Ukuze kuqinisekiswe ukuba i-core of casting inezixhobo eziyimfuneko zomatshini kunye nesakhiwo se-metallographic, kunye nokunciphisa ukuguqulwa emva kwe-nitriding, unyango lwangaphambili ngaphambi kokuba i-nitriding iyadingeka. Kwintsimbi yesakhiwo, ukucima kunye nonyango olushushu luyafuneka ngaphambi kokuba i-nitriding ifumane i-uniform kunye ne-fine tempered sorbite isakhiwo; ukwenzela ukuphosa okugqwethekileyo ngokulula ngexesha lonyango lwe-nitriding, unyango lwe-annealing annealing luyafuneka emva kokucima kunye nokuvutha; ngenxa yentsimbi engatyiwayo kunye neentsimbi ezixhathisa ubushushu zingacinywa ngokubanzi kwaye zibe nomsindo ukuphucula ubume kunye namandla; kwi-austenitic steel stainless, unyango lobushushu lwesisombululo lunokusetyenziswa.