The First Step (Degreasing) of the procedure is designed to remove dirt, dust, oil and grease. A water-soluble detergent is used to accomplish this, or a solvent.
第一步（去油）：去除污垢、灰尘、油和脂。使用水溶性去污剂或溶剂来完成该步骤。
2
Steel surface should be no visible grease and dirt, and there is no attachment not firm scale, rust, paint and other impurities (watersoluble salt and welding residue).