Products

NCM CHROME S CHROMIUM COATING

NCM CHROME S
is an additive for preparation of electrolytic solution for
Nano chroming
Product form / solution

Advantages

High thermal and chemical stability of NCM Chrome component

High throwing power and metal deposition over micro profile and macro profile

Increased heat resistance

Micro-hardness variation range about
670-850 HV 0.1
at
68-75° С and 950-1,370 HV 0.1
at 54-58° С. Current density increase from 25 A/dm2 to 80 A/dm2
enhances micro-hardness of coatings

High capacity for further polishing

Reduction of time, essential for chroming by 2 times (40-55%) if compared with ordinary electrolytes. Chroming speeds range from
0.4 to 1.5 µm/m

Provision of low crystallinity and required micro fissures amounts (determined by customer’s requirements)

Decreased power consumption of about
40-50%, if compared with universal electrolyte for chroming

Dry friction coefficient of NCM Chrome coating (ST-40 indenter, VK6 hard alloy) is
0.05-0.07.
High fretting corrosion resistance.

NCM Chrome
is a high efficiency method of hard, wear-resistant and corrosion-resistant decorative chroming without fluoride applications with high current efficiency. It allows for creation of glossy, hard, wear-resistant and corrosion-resistant chromium coatings by means of variation of current, temperature and hydrodynamic modes, coating thickness and modifying additive contents.

Technological, exploitation and environmental advantages

  • Lack of fluorinated components
  • Reduction of chromium anhydride concentration in electrolyte by 30-35%
  • Reduction of electrolyte outflow with technological satellites and vent emission by 45-55%
  • Application of additional foam generating agents and mist extractors is not required thanks to a small size of gas electrode products beads and electrolyte mirror surface tension
  • Compliance with electrolytes, not containing fluorides
  • NCM Chrome coatings are suitable to all brands of carbon and stainless steel, copper and copper alloys, wrought aluminum alloys and high-silicon aluminum alloys as well as different brands of cast iron. NCM Chrome electrolytes have a minimum pickling ability, if applied to items like copper, copper alloys, aluminum and aluminum alloys. It allows precision processing over such items. During the chroming process, electrolytes are minimally deteriorated by metal details and jigs ions.
  • NCM Chrome electrolyte possesses minimum environmental hazard generalized criterion, if compared with other electrolytes, applied for chroming, requires low amounts of water for flushing and is characterized by low main component outflow.
  • Current efficiency at high current density is at 23.5-25%. Voltage during electrolysis varies from 3.9V to 6.8V, depending on the current density, temperature, hydrodynamic mode, type of items, the location in their electroplating bath, anodes condition and the reliability of electric contacts.
  • Electrolyte recirculation and electrochemical regeneration is available
  • NCM Chrome chromium coating is the most economically viable. NCM Chrome coating requires minimum power consumption for temperature mode stabilization.
  • Essential characteristics of one-layered, two-layered, three-layered and superfine NCM Chrome coatings are provided at temperature modes from 40°С to 70°С. Steady and unsteady current loads from 10 A/dm2 to 100 A/dm2 and hydrodynamic mode. In case of electrolyte flow, chroming at higher current density is available.
  • NCM Chrome application provides the most favorable conditions for anodes long-term exploitation, because of the lack of lead chromate complex forming at the surface of lead anodes and application of 4-8% of stannic and stibium. Application of wear-resistant titanium-based membrane anodes is available.
  • CrO3 content in electrolyte does not exceed 170g/l + various modifications of NCM Chrome additives.
  • NCM Chrome chromium coating technology has been successfully applied in Russia, China and Taiwan in such spheres as multifunctional chromium coating of vehicle rods, hydraulic cylinder elements, flow compartments of oil pumps, die molds for various kinds of plastic, various details for textile industry, crystallization vats for continuous steel casting machines, oversized gate valves and other special equipment within 3 years. Nanostructured fine NCM Chrome coatings under 1 µm for polished stainless steel possesses unique decorative and wear-resistant properties which can be applied for modern design and finishing constructions of various dimensions for interior and exterior.

Required equipment

Rectifier unit

Flex Kraft steps programmable reversible rectifiers with output signal linear scanning ability is desirable

Continuously variable reversible rectifiers can be also applied

Continuous filtration

Not required

Electrolyte agitation

Barbotage by purified air

Warming / Cooling

Heating device of porcelain, titanium alloys or PTFE coatings

Air extraction

Required (equipped with a filter for aerosol ventilation emissions entrapment)

Voltage

12–24 V

Anodes

Anodes of lead-stibium (5-8% Sb) or lead-stannic (4-7% Sn) alloys or platinum-titanium anodes are recommended

General requirements in detail

Sharp angles and edges of detail, except for technical based cases, shall be rounded at a radius less than 0.5 mm.

Rolled-in scales, burrs, laminations and flaws, including those that were discovered after pickling, polishing and grinding. Corrosion damages, voids and blowholes on the surface of a detail are not allowed.

The surface of details after machine processing shall not contain any visible layer of lubricant or emulsion, metal chips, burrs, dust, corrosion products and also tramp metal particles.

Welded and soldered seams on details shall be ground continuously across the whole ambit, except for splits for penetration of solution.

Detail surface undulation shall not exceed Ra 1.25.

Plough defects, dimples, burns, guide marks, burrs, defects caused by a flattener.

Chromium coated details undergo the following procedures:

  • Chemical or electrochemical degreasing
  • Warm flushing at 45-60°С
  • Chemical activation
  • Flushing
  • Chroming
  • Entrapment flushing
  • Flushing
  • Drying.

Imporosity

DURAMIN 5 micro hardness tester (Denmark)

Black NCM Chrome

Variation of throwing power, determined by NCM concentration (ic = 50 A/dm2, T = 55°С)

Variation of dry friction coefficient for NCM Chrome coating
ST-40 indenter

Depiction of NCM Chrome coating chip structure with relevant nanostructured components presented by netting

Map of Nano sized component contents of NCM Chrome coating chips

Application of NCM Chrome coatings in the manufacturing industry

China chrome
HV 0.1 850±50

Switzerland chrome
HV 0.1 750±50

NCM Chrome
HV 0.1 1050±50

Chromium coating of cutting tools, including band saws of textile equipment

NCM Chrome electrolyte allows for coating cutting tools with enhanced hardness, wear-resistance of coating, current efficiency around 22-24% at increased current density without formation of knobs and dendrites on sharp teeth, which substantially increases operational life and performance quality of cutting tools.

Chromium coating of vehicle shock absorber rods and gas strut rods

NCM Chrome electrolyte HV 0.1 1100-1370
Current efficiency 22-24 %
Chroming speed up to 1.5 µm/min

Chromium coating of inner surface of various purpose pipes, including casing pipes of oil pumps

Chromium coating of textile equipment details, including shuttle rings

NCM Chrome electrolyte allows chromium coating of shuttle rings with a high speed (up to 1.3 µm/min) and wear-resistance. Coating has no knobs and dendrites and does not require additional polishing as well; it’s characterized through enhanced operational life cycle.

Chromium coating of crystallization vats for continuous steel casting machines

NCM Chrome electrolyte provides:

  • High speed of chroming with minimum energy consumption;
  • Voltage for chroming processes not exceeding 4.2 V;
  • Equal coating thickness across the whole length and inner surface of crystallization vat;
  • Enhanced operational life of crystallization vats for continuous steel casting machines with application of fine coatings, if compared with traditional coatings.

Leader Enterprise, Taiwan, LEADER EXTRUZION MACHINERY IND. CO., LTD, Taiwan

Chromium coating of die molds for thermoplastics

NCM Chrome electrolyte provides:

  • High speed chroming with minimum energy consumption;
  • Equal coating thickness;
  • Provision of required micro fissures amount and low crystal density;
  • Provision of undulation of mating surfaces;
  • High capacity for further polishing;
  • Enhancing hardness and wear-resistant surface and load capacity under compression;
  • Enhancing sliding characteristics, retrievability, and corrosion resistance;
  • Enhanced operation with the application of fine coatings, if compared with traditional coatings;

Chromium coating of functional units of heavy industry reinforcement for oil and gas pipelines

Tyazhpromarmatura, CJSC, Tula Region, Alexin City

Chromium coating of pipelines gate valves

Porosity control over the whole surface by paste applying method under State Standard 9.302-88

Micro hardness of gate valve control. DuraScan device

Requirements

Microhardness
1000 – 1200 HV0.1.

Undulation
Ra up to 0.4 µm

Adhesion
Heat processing at 300°С for 2 hours with absence of visual defects.

Unequal deposition over surface
Up to 40 µm

Porosity
0.02 pores/cm2 (requirement under State Standard 9.302-88 is 2 pores/cm2)

NCM Chrome coating parameters on gate valves

Micro hardness
1120 – 1230 HV0.1.

Undulation
Ra 0.08-0.22 µm.

Adhesion
No visual defects after heat processing of 300°С.

Unequal deposition over surface
up to 7-18 µm.

Porosity
Absent

Chromium coating of gas pipelines plugging

Porosity control is conducted by method of paste applying to the plugging and by method of application of filter paper to witness-samples

Requirements

Micro hardness
1000 – 1200 HV0.1.

Undulation
Ra up to 0.8 µm

Adhesion
Heat processing at 300°С for 2 hours. Absence of visual defects

Unequal deposition over surface
Up to 40 µm

Porosity
0.02 pores/cm2 (requirement under State Standard 9.302-88 is 2 pores/cm2)

NCM Chrome coating parameters on gate valves

Micro hardness
1120 – 1230 HV0.1

Undulation
Ra 0.17-0.35 µm.

Adhesion
No visual defects after heat processing at 300°С.

Unequal deposition over surface
4-10 µm.

On radii without shields:
15-30 µm.

Porosity
Absent

Order form
  • CAPTCHA
* Mandatory Fields