SCALE REMOVER FOR STAINLESS STEEL

PROBLEM TO BE SOLVED: To provide a scale remover for stainless steel which does not contain hazardous hydrofluoric acid, can remove scale at the time of welding of stainless steel at room temperature, and does not produce sediment even at low temperature.SOLUTION: A scale remover for stainless steel contains an aqueous solution containing nitric acid, citric acid, a chelating agent, and an amphoteric surfactant, and further contains hydrochloric acid and a nitrate. Preferably, the concentration of the nitric acid is 2 mass% or more and 15 mass% or less, the concentration of the citric acid is 7 mass% or more and 20 mass% or less, the concentration of the chelating agent is 0.6 mass% or more and 1.7 mass% or less, the concentration of the amphoteric surfactant is 3.0 mass% or more and 10 mass% or less, and preferably, the concentration of the hydrochloric acid is 0.05 wt% or more and 1.5 wt% or less, and the nitrate is potassium nitrate and is 5 mass% or more and 10 mass% or less.SELECTED DRAWING: None 【課題】有害なフッ化水素酸を含んでおらず、室温でステンレス鋼の溶接時のスケールを除去することができ、低温下においても沈殿物が生じないステンレス用スケール除去剤の提供。【解決手段】硝酸、クエン酸、キレート剤、及び両性界面活性剤を含む水溶液であって、さらに塩酸及び硝酸塩を含むステンレス用スケール除去剤。硝酸の濃度は２質量％以上１５質量％以下、前記クエン酸の濃度は７質量％以上２０質量％以下、前記キレート剤の濃度は０．６質量％以上１．７質量％以下、前記両性界面活性剤の濃度は３．０質量％以上１０質量％以下であることが好ましく、塩酸の濃度は０．０５質量％以上１．５重量％以下、前記硝酸塩は硝酸カリウムであって５質量％以上１０質量％以下であることが好ましいステンレス用スケール除去剤。【選択図】なし