A.焊接時(shí)間長 B.焊接時(shí)間短 C.焊接時(shí)間較短 D.造成虛焊假焊、漏焊
A.(250±5)℃ B.(250±2)℃ C.(350±2)℃ D.(350±5)℃
A.涂焊劑一預(yù)熱一冷卻一清洗 B.涂焊劑一預(yù)熱一波峰焊一冷卻一清洗 C.涂焊劑一冷卻一波峰焊一預(yù)熱一清洗 D.涂焊劑一預(yù)熱一清洗一冷卻