Self-tapping screws los yog ceev - teem screws yog ceev - teem fasteners ua los ntawm steel, galvanized thiab passivated. Tapping screws yog siv los txuas cov hlau nyias (steel plates, saw plates, thiab lwm yam). Thaum sib txuas, ua ntej ua cov xov hauv qab ntawm qhov txuas, thiab tom qab ntawd ntswj lub tapping ntsia hlau rau hauv cov xov hauv qab ntawm qhov txuas.
Carburizing yog txheej txheem ntawm kev xaj cov pa roj carbon atoms rau hauv cov hlau nto, ua rau cov hlau nto tshuaj lom neeg nyob ze rau cov pa roj carbon ntau, rau cov hlau tsis tshua muaj siab carbon steel hardness, hnav tsis kam thiab qaug zog ntawm cov ntaub ntawv carburized rau cov pa roj carbon tsawg lossis cov pa roj carbon tsawg. Feem ntau cov tsoos roj carburizing tshuab, feem ntau yog cov txheej txheem carburizing decomposition, adsorption thiab diffusion theem.
Cov txheej txheem carburizing ntawm tapping ntsia hlau yog txawv ntawm cov txheej txheem nruab nrab thiab tob carburizing. Rau lub workpiece nrog qhov tob ntawm txheej infiltration ntau dua 1. over-eutectomized txheej thiab eutectomized txheej ntawm infiltration txheej yuav muaj tej yam yuav tsum tau.
Txhawm rau kom ntseeg tau tias muaj kev kub ceev carburizing, cov khoom siv no feem ntau siv cov pa roj carbon ntau muaj peev xwm carburizing cov pa roj carbon ntau ntawm 0.7 feem pua -0.8 feem pua C cua rau kev nthuav dav. Txhawm rau txo qhov cuam tshuam los ntawm kev sib tsoo ncaj qha tom qab carburizing thiab txo cov qib ntawm martensite thiab residual austenite, nws yuav tsum tau hais tias tom qab lub diffusion theem, lub cub tawg yog txias rau 820-860 degree isothermal thiab ces quench, thiaj li mus xyuas kom meej tias cov txheej txheem infiltration thiab lub plawv muaj peev xwm hardness thiab zoo microstructure. Cov txheej txheem carburizing no muaj cov kev xav tau sib txawv rau cov khoom siv roj thiab cov roj muaj zog piv nrog tapping ntsia hlau carburizing.
