| POLIGRAT GMBH Patent applications |
| Patent application number | Title | Published |
|---|
| 20110309296 | METHOD FOR THE SURFACE TREATMENT OF STAINLESS STEEL - In a method for surface treatment of stainless steel, the thermally produced layers of oxide are contacted with a composition effective to dissolve iron ions out of the layers of oxide. | 12-22-2011 |
| 20100132844 | METHOD FOR THE THERMOCHEMICAL PASSIVATION OF STAINLESS STEEL - The present invention relates to a process for improving the heat and corrosion resistance of stainless steel by means of a novel passivation process. This process comprises a chemical treatment with an aqueous solution comprising a complexing agent combination of at least one oxidant, a subsequent rinsing and a subsequent treatment at elevated temperature in an oxygen-containing atmosphere. The stainless steel surfaces obtained according to the invention have a homogeneous passive layer having increased chemical resistance and resistance to thermal discoloration. | 06-03-2010 |
| 20090200178 | ELECTROPOLISHING METHOD - The present invention describes a cost-saving and environmentally conserving process for the electrochemical polishing of steel, in particular of low-alloy steels. The workpieces are rinsed after electropolishing in an arid phosphoric acid-sulfuric acid-bath in a first rinsing step with a phosphoric acid-containing solution, whereby a chemical attack on the freshly polished surfaces is avoided without the use of environmentally harmful and unhealthy inhibitors such as chromates. By recycling of the acids and the rinsing solution, these acids and solutions can be regenerated, whereby the process can be designed effluent-free. | 08-13-2009 |
| 20080289970 | ELECTROPOLISHING PROCESS FOR COBALT AND COBALT ALLOYS - The present invention relates to a method of electrochemical polishing of surfaces of cobalt or cobalt alloys. It employs an electrolyte comprising glycolic acid and at least one alkane-sulfonic acid with an alkyl residue that has 1 to 3 carbon atoms. This electrolyte is also one aspect of the present invention. In one embodiment, at least one alkane-sulfonic acid comprises methane-sulfonic acid. The electrolyte and the method using this electrolyte are suitable in particular for surfaces of cobalt or cobalt alloys, including cobalt-chromium alloys such as stellite. | 11-27-2008 |
| 20080217186 | Electropolishing process for titanium - The present invention relates to a method of electrochemical polishing of surfaces of titanium or titanium-containing alloys, such as Nitinol. An electrolyte is used that comprises methanesulfonic acid and one or more alkanediphosphonic acids. These alkanediphosphonic acids can optionally be substituted with hydroxy and/or amino groups. A further aspect of the present invention relates to the use of said electrolyte for the electropolishing of titanium or titanium-containing alloys. | 09-11-2008 |
