摘要:
The invention relates to a method for one-bath chemical cleaning and preservation of interior surfaces of hollow steel bodies) without any organic solvents, comprising controlled change of the liquid bath in that in a circuit of hoses running from a mobile tank equipped with a pump unit and steam generator there is circulated a liquid stream to a defined cavity of steel. The composition of the liquid is changed methodically by the addition of fresh chemical additives until the end of the process. Fresh water at 80° C. has added thereto an alkaline degreasing liquid A containing chlorine-free tensides, which is circulated, whereupon cleaning liquid B, consisting of citric acid with added cationic tensides, is added to a pH of 4.5 and is circulated. There is then added a complexing derusting liquid C, with active modified aminocarboxykate made biologically degradable, with adjustment of the pH to 4.5-5.0 with cleaning liquid B, and extra addition of the complexing agent if derusting liquid C falls below 5% by weight, until the iron content of the liquid is stable. For passivation, a non-ionic passivating and neutralising liquid D, consisting of alkaline degreasing agent and non-ionic, chlorine-free tensides, is added to pH 7.0-7.5, after which there is added 2-4% by weight of inhibiting liquid E, consisting of a chain molecule of a chelate, active at pH >7, which functions as a supplement to the aminocarboxylate. A gluconate with heptanate and silicate provides a diffusion-proof microfilm on the steel surface.
摘要:
Fluoride-containing scale can be removed from metal surfaces such as titanium, titanium alloys, nickel alloys, and stainless steel by contacting the metal surfaces with an aqueous salt solution of an inorganic acid, including its hydrates. The cationic portion of the salt can be aluminum, iron and mixtures thereof. The anionic portion of the salt can be a chloride, a nitrate, a sulfate, and mixtures thereof. The contracting occurs in the absence of the addition of an acid, such as hydrochloric, nitric, or sulfuric acid. The presence of the aqueous salt solution with the dissolved fluoride scale does not accelerate or increase the normal rate of metal corrosion that can occur in the absence of the aqueous salt solution or any acidic cleaning agent.
摘要:
The present invention provides a solvent mixture comprising n-Propyl bromide, a mixture of terpenes and a mixture of low boiling solvents, and a method for cleaning an article (e.g., an electrical, plastic, and metal parts) in a vapor degreaser using the solvent mixture. The solvent mixture of the present invention is non-flammable, noncorrosive and non-hazardous. In addition, it has a high solvency and a very low ozone depleting potential. Thus, using the solvent mixture of the present invention, oil, grease, rosin flux and other organic material can be readily removed from the article of interest in an environmentally safe manner.
摘要:
The invention provides a solvent mixture including n-propyl bromide, a mixture of low boiling solvents and, preferably, a defluxing and/or ionics removing additive and/or at least one saturated terpene. The invention also provides a method of cleaning an article (e.g., an electrical, plastic, or metal part) in a vapor degreaser using the solvent mixture. The solvent mixture of the invention is non-flammable, non-corrosive, and non-hazardous. In addition, it has a high solvency and a very low ozone depletion potential. Thus, using the solvent mixture of the invention, oil, grease, rosin flux, and other organic material can be readily removed from the article of interest in an environmentally safe manner.
摘要:
The present invention provides a solvent mixture comprising n-propyl bromide, a mixture of terpenes and a mixture of low boiling solvents, and a method for cleaning an article (e.g., an electrical, plastic, and metal parts) in a vapor degreaser using the solvent mixture. The solvent mixture of the present invention is non-flammable, non-corrosive and non-hazardous. In addition, it has a high solvency and a very low ozone depleting potential. Thus, using the solvent mixture of the present invention, oil, grease, rosin flux and other organic material can be readily removed from the article of interest in an environmentally safe manner.