化學(xué)配方數(shù)據(jù)庫(kù)
| 配方類型： |
METALS |
| 配方說(shuō)明： |
Hot-Tinning of Cast Iron |
| 配方組成： |
Hydrochloric acid/2 pt
Sodium chloride/6 lb
Water/10 gal (100 lb)
Ammonium chloride/3 lb
All surfaces of the piece must be wetted by the flux. The delay
between operations 1 and 3 should be kept as short as possible.
4. The piece is then lowered slowly into the first tinning pot, the
surface of which is covered by a layer of flux at least one inch thick.
The flux contains
Zinc Chloride/8
Zinc chloride/24 lb
Sodium Chloride/2
Ammonium Chloride/1 |
| 配制方法： |
and must be kept boiling freely be frequent additions of water. With large articles, which must necessarily be immersed rather slowly, there may be some risk of the aqueous flux drying on the upper parts before immersion is complete. This will inevitably lead to imperfect tinning and must be prevented by spraying with water or with the aqueous flux from a fine rose or any simple spray gun. The temperature of the tin should be 300-320C.
5. Although the piece should accept the tin within one minute, it is advisable to allow it to remain in the tin pot for at least five minutes. This length of time allows flux residues to escape and greatly minimizes risk of "sweating" in the finished coating.
6. After removal from the first tin pot, subsequent tinning and other manipulations are as normally practiced.
Although the direct chloride process has been used mostly for protective tin coatings, some information is available onn results to be expected when the method is used as preliminary to bonding ba |
|
