重点介绍直流锅炉氢氟酸酸洗的目的，方法及过程，还对不同介质的化学清洗进行了比较。

This article introduces the purpose, method and procedure of HF acid chemical clean for once through boiler, and comparison between chemical clean of different mediums is presented as well.

论述了氢氟酸对碳钢的腐蚀规律，并介绍了碳钢设备和碳钢氩弧焊丝的合理选材。

The regular corrosive patterns of carbon steel in hydrofluoringe acid are mentioned. The reasonable selection of carbon steel and carbon steel argon arc welding wire are introduced.

试样用硝酸—氢氟酸溶解，硫酸冒烟后强碱分离钛、铁、镍离子，其余干扰离子用酒石酸钾钠掩蔽。

The sample is dissolved in nitric and fluoric-hydro acid adding sulfuric acid, and heating up to fuming, then the matrix element titanium is separated with sodium hydroxide.

氢氟酸(HF)为一无色略带刺激味的无机酸，普遍地被使用于各种工业，如半导体工业及金属除锈等。

Hydrofluoric acid (HF), a colorless inorganic acid with mild irritating odor, is used extensively in various industries, such as the semiconductor industry and the electropolishing of metal.

逆土酸系指氢氟酸浓度和用量高于盐酸浓度和用量的土酸，它处理地层的机理与土酸相同。

The reversed mud acid is the mud acid whose concentration and volume of hydrofluoric acid is higher than that of hydrochloric acid, its treatment mechanism is identical to the mud acid.