Cov khoom siv raw ntawm cov kav hlau welded yog cov pa roj carbon tsawg tsawg, cov hlau tsis tshua muaj hlau lossis cov hlau manganese siab, thiab lwm yam, uas tau siv dav hauv boilers, tsheb, nkoj, lub teeb steel qauv qhov rooj thiab qhov rais, rooj tog, ntau yam kev ua liaj ua teb machinery, high- nce rhawv, ntim, thiab lwm yam. Yog li wh...
Nyeem ntxiv