Durachrom

Protective coatings according to DURACHROM technology, used as anti-corrosion protection on cylinder rods and core prints of hydraulic props, are more resistant to corrosion-forming agents than conventional coatings, and the applied materials and production processes do not constitute any hazard for the natural environment.

The presented range of production solutions effectively replaces all standard anti-corrosion coatings of galvanic type such as chromium, nickel, nickel-chromium etc., however with some minor economic limitations. Confrontation with electroplating entailed comparing unit prices of making one square decimetre of the reference coatings. So far, DURACHROM coatings do not win such confrontation for typical sizes of rods and core prints with diameters smaller than 80 mm, at lengths below ca. 0.5 m. In relation to a high content of chromium and nickel DURACHROM coatings are resistant to atmospheric corrosion, natural water (including marine water and mine water), medium-concentrated saline solutions, alkaline solutions, low-concentrated organic acids and the majority of inorganic acids.

As compared to typical electroplated chromium coatings, DURACHROM coatings are far more elastic – they do not crack at high compressive (tensile) stress in the rod or core print core or do not chip as a result of spot, local dynamic loads of the coating surface.

As compared to electroplated copper coatings, DURACHROM coatings have a much higher resistance to corrosion and mechanical strength, particularly as far as resistance to wear is concerned. The best technical and economic effects of using DURACHROM technology coatings can be observed at repairs of external surfaces of rods and core prints of large hydraulic cylinders, props and brackets in particular. The benefits result not only from a large quantity of the renovated surface dm2 but also from significant savings as a result of the possibility to eliminate padding to ensure the renovated surface recovery to the nominal dimension after the repair, even if the depth of corrosion pits exceeded ca. 0.5-0.7 mm.

Nominal dimensions
Diameter of piston rod Geometry of coat Geometry of coat Diameter of piston rod Geometry of coat Geometry of coat Diameter of piston rod Geometry of coat Geometry of coat
d nominal G min L max d nominalna G min L max d nominal G min L max
40 0,65  850 140  0,75 2000 270    0,75* 2500
50 0,65  850 150 0,75* 2000 275    0,75* 2500
55 0,65  850 160 0,75* 2000 280    0,75* 2500
56 0,65  850 180 0,75* 2000 285    0,75* 2500
60 0,65  850 185 0,75* 2000 305    0,75* 2500
63 0,65  850 190 0,75* 2000 315    0,75* 2500
70 0,65  850 195 0,75* 2000 320    0,75* 2500
80 0,65  850 200 0,75* 2000 330    0,75* 2500
90 0,65  850 210 0,75* 2500 350    0,75* 2500
95 0,75 2000 225 0,75* 2500 355    0,75* 2500
100 0,75 2000 230 0,75* 2500 370    0,75* 2500
110 0,75 2000 240 0,75* 2500 380    0,75* 2500
115 0,75 2000 245 0,75* 2500 390    0,75* 2500
120 0,75 2000 250 0,75* 2500 400    0,75* 2500
125 0,75 2000 260 0,75* 2500 410    0,75* 2500
130 0,75 2000 265 0,75* 2500 410    0,75* 2500
After-repair dimensions
Diameter of piston rod Geometry of coat Geometry of coat Diameter of piston rod Geometry of coat Geometry of coat
d nominal G min L max d nominal G min L max
77,5 0,65 850 159 0,75* 2000
78,8 0,75 2000 186 0,75* 2000
97,5 0,75 2000 187,5 0,75* 2000
98,8 0,75 2000 188,8 0,75* 2000
112,5 0,75 2000 193,8 0,75* 2000
113,8 0,75 2000 194 0,75* 2000
114 0,75 2000 197,5 0,75* 2000
137,5 0,75 2000 198,8 0,75* 2000
138,5 0,75 2000 237,5 0,75* 2500
139 0,75 2000 238,8 0,75* 2500

* it is possible to apply external coats in special version:

  • coat thickness G=1,2 mm
  • diameter d within the tolerance h8, f9 and others
  • surface roughnes Ra=0,8 or Ra=0,4