常見例句雙語例句Preheating shall also be applied to the tack welding, when the weldment requires preheating.需要預(yù)熱的焊件，定位焊時也應(yīng)按規(guī)定進行預(yù)熱。chazidian.comThe UN250 butt-welding machine adopts manual flash prewarming, hydraulic pressure upset mode, is suitable to weld large diameter and section weldment.UN250對焊機采用手動閃光預(yù)熱、液壓頂鍛的方式，適合焊接大直徑大截面的焊件。chazidian.comHeating and cooling a weldment in such a way as to obtain desired properties.為了獲得期望的特性，對焊接件進行的加熱及冷卻。cid-1136830e27e23174.spaces.live.com 返回 weldment