玻璃瓷和瓷搪瓷 - 耐化学腐蚀的测定 - 第2部分:通过沸腾酸 沸腾的中性液体 碱性液体和/或其蒸汽测定耐化学腐蚀性Vitreous and porcelain enamels - Determination of resistance to chemical corrosion - Part 2: Determination of resistance to chemical corrosion by boiling acids, boiling neutral liquids, alkaline liquids and/or their vapours