Carbonitration
Description
Our company “Karbaz” offers a whole range of new hardening technologies. One of them is carbonitriding as a chemical-thermal treatment of metals. During this process, the products are gradually saturated with nitrogen and carbon.
Carbonitriding of steel and cast iron allows to significantly increase the strength and wear resistance of parts by 2-11 times, and to delay the onset of the corrosion process as much as possible.
All grades of cast iron and steel can be subjected to carbonitriding. The following parts are most often carbonitrided:
– gears and cogwheels;
– augers, sprockets and worms;
– pump motors;
– shut-off valves;
– compressors;
– tool
(loader augers, drums, crankshafts, bushings, harrow disks, sprockets, harrow teeth, toothed wheels, bearing housings, bearings, brackets, knives, choppers, gearbox axles, rear axle half-shafts, springs, tension rollers, plow blade, sieves, flanges, gears, pulleys, etc.)
According to the technology, the process of liquid carbonitriding is carried out in a melt of carbonate and cyanate salts at a temperature of 540-600 degrees Celsius. The cutting tool is kept in such a melt for 50 minutes, while for hardening of parts and mechanisms, it is necessary to keep it from 2 to 8 hours.
Our technical capabilities for carbonitriding
- The lifting capacity of crane equipment is up to 2 tons.
- The capacity of the section is up to 4 tons/day
- The work will be completed within 1-2 working days.
STRENGTHENING OF RING-TYPE PARTS WITH A DIAMETER OF UP TO 940 MM. HEIGHT OF UP TO 500 MM
(up to 950 mm using the “overturn” technology).
STRENGTHENING OF SHAFT TYPE PARTS WITH A DIAMETER OF UP TO 420 MM. LENGTH OF UP TO 2300 MM.
(up to 4500 mm using the “overturn” technology).The technology also allows for local hardening with partial immersion of parts in the melt.
Our technical capabilities for carbonitriding
- The lifting capacity of crane equipment is up to 2 tons.
- The capacity of the section is up to 4 tons/day
- The work will be completed within 1-2 working days.
STRENGTHENING OF RING-TYPE PARTS WITH A DIAMETER OF UP TO 940 MM. HEIGHT OF UP TO 500 MM
(up to 950 mm using the “overturn” technology).
STRENGTHENING OF SHAFT TYPE PARTS WITH A DIAMETER OF UP TO 420 MM. LENGTH OF UP TO 2300 MM.
(up to 4500 mm using the “overturn” technology).The technology also allows for local hardening with partial immersion of parts in the melt.
ADVANTAGES OF CARBONITRATION
Any grades of steel and cast iron
- Strengthening of parts made of any grade of steel and cast iron
High quality indicators
- Increase in wear resistance of parts by 2-11 times
- Increase in fatigue strength of parts by 50-80%
- Decrease in friction coefficient by 1.5-5 times
- Increase in corrosion resistance of "black" steels
Efficiency and economy
- High saturation rate (0.5-6 hours)
- Uniform heating and saturation in the melt
Without additional processing
- No brittleness of the carbonitrided layer
- Finishing – finished parts are processed
In many cases, carbonitriding is much more profitable than hardening, nitriding, nitrocarburizing, phosphating or galvanic chromium plating. The result is a non-brittle surface layer, the quality of which largely depends on the degree of alloying of the steel: the more the metal is saturated with nitride-forming elements, the stronger this layer is.
Our company “Karbaz” has equipment that produces liquid carbonitriding 4 tons / day, so this service is provided very quickly – within 1-2 days.
If you decide to perform carbonitriding, then leave requests on the website, and if you have questions, then call a representative of our company by phone.
MAIN PROCESS PARAMETERS
Diffusion saturation of the surface of steel and cast iron products with nitrogen and carbon
Protection of machine parts and tools from wear, erosion, corrosion, fatigue and contact failure
Melt of cyanates and carbonates
540-600°С
5-45 min - for cutting tools
1-8 hours - for stamping tools and machine parts
Iron-based alloys (all grades of steel and cast iron)
Gear wheels, pinions, shafts, crankshafts, rods, lead screws, sprockets, worms, augers, engine parts, pumps, shut-off valves, screw, piston, centrifugal compressors and many other rubbing and quickly wearing parts. Cutting, stamping, pressing, drawing and other tools
CARBONITRATION TECHNOLOGY
STRUCTURE AND PROPERTIES OF THE CARBONITRIED LAYER
LAYER DEPTH AND HARDNESS
Parameters of the carbonitrided layer for various grades of steel and alloys
| Марка стали | Толщина карбонитрированного слоя | Твёрдость карбонитрированного слоя | ||
| Общая толщина слоя (карбонитридная и дифузионная зона) h, мм | Толщина слоя соединений (карбонитридная зона (Е-фаза) h, мкм | По Виккерсу, НV (при нагрузке 5 кгс (HV5) или 10 кгс (HV10)) | По Супер-Роквеллу, HRN (при нагрузке 15 кгс (HRN15)) | |
| Ст.3 | 0,1-0,6 | 5-25 | 380-430 | 79-83 |
| 08 кп | 0,1-0,6 | 380-430 | 79-83 | |
| 10 | 0,1-0,6 | 380-430 | 79-83 | |
| 15 | 0,1-0,6 | 380-430 | 79-83 | |
| 20 | 0,1-0,6 | 400-450 | 81-84 | |
| 30 | 0,1-0,6 | 400-450 | 81-84 | |
| 35 | 0,1-0,6 | 400-450 | 81-84 | |
| 45 | 0,1-0,6 | 450-550 | 84-86 | |
| Марка стали | Толщина карбонитрированного слоя | Твёрдость карбонитрированного слоя | ||
| Общая толщина слоя (карбонитридная и дифузионная зона) h, мм | Толщина слоя соединений (карбонитридная зона (Е-фаза) h, мкм | По Виккерсу, НV (при нагрузке 5 кгс (HV5) или 10 кгс (HV10)) | По Супер-Роквеллу, HRN (при нагрузке 15 кгс (HRN15)) | |
| 20Х | 0,1-0,6 | 5 – 25 | 550-650 | 86-89 |
| 30Х | 0,1-0,6 | 550-650 | 86-89 | |
| 35Х | 0,1-0,6 | 550-650 | 86-89 | |
| 40Х | 0,1-0,6 | 550-650 | 86-89 | |
| 38ХМ | 0,1-0,6 | 600-700 | 88-90 | |
| 40ХФА | 0,1-0,6 | 600-700 | 88-90 | |
| 40ХМФА | 0,1-0,6 | 600-700 | 88-90 | |
| 38Х2МЮА | 0,1-0,6 | 800-1200 | 92-95 | |
| 25Х1М1Ф | 0,1-0,6 | 650-750 | 89-91 | |
| 25Х2М1Ф | 0,1-0,6 | 650-800 | 89-92 | |
| 55С2 | 0,1-0,4 | 500-600 | 85-88 | |
| ШХ15 | 0,1-0,4 | 500-600 | 85-88 | |
| 09Г2С | 0,1-0,5 | 450-550 | 84-86 | |
| 30ХН2МФА | 0,1-0,6 | 600-700 | 88-90 | |
| 18Х2Н4ВА | 0,1-0,6 | 700-850 | 90-93 | |
| 12Х2Н4А | 0,1-0,6 | 600-700 | 88-91 | |
| 38ХH3МФА | 0,1-0,6 | 600-750 | 88-91 | |
| 18ХГТ | 0,1-0,6 | 600-750 | 88-91 | |
| 30ХГТ | 0,1-0,6 | 600-750 | 88-91 | |
| 30ХГСА | 0,1-0,6 | 600-750 | 88-91 | |
| 40Х2Н2МФА | 0,1-0,6 | 650-800 | 89-92 | |
| 36Х2Н2МФА | 0,1-0,6 | 650-800 | 89-92 | |
| 20Х3МВФ | 0,1-0,55 | 700-900 | 90-93 | |
| 30Х3МФ | 0,1-0,55 | 650-750 | 89-91 | |
| 38ХГН | 0,1-0,55 | 550-700 | 86-90 | |
| Марка стали | Толщина карбонитрированного слоя | Твёрдость карбонитрированного слоя | ||
| Общая толщина слоя (карбонитридная и дифузионная зона) h, мм | Толщина слоя соединений (карбонитридная зона (Е-фаза) h, мкм | По Виккерсу, НV (при нагрузке 5 кгс (HV5) или 10 кгс (HV10)) | По Супер-Роквеллу, HRN (при нагрузке 15 кгс (HRN15)) | |
| 3Х2В8 | 0,06-0,12 | 5-25 | 1000-1150 | 94 |
| Х12М | 0,06-0,12 | 1000-1150 | 94 | |
| 4Х5МФС | 0,06-0,12 | 1000-1150 | 94 | |
| 4Х3В3МФС | 0,06-0,12 | 1000-1150 | 94 | |
| У8 | 0,1-0,4 | 550-650 | 86-89 | |
| 9ХС | 0,1-0,4 | 550-650 | 86-89 | |
| ХВГ | 0,1-0,4 | 550-700 | 86-90 | |
| 5ХНМ | 0,1-0,6 | 650-750 | 89-91 | |
| Р18 | 0,01-0,03 | 1000-1150 | 94 | |
| Р6М5 | 0,01-0,03 | 1000-1150 | 94 | |
| Марка стали | Толщина карбонитрированного слоя | Твёрдость карбонитрированного слоя | ||
| Общая толщина слоя (карбонитридная и дифузионная зона) h, мм | Толщина слоя соединений (карбонитридная зона (Е-фаза) h, мкм | По Виккерсу, НV (при нагрузке 5 кгс (HV5) или 10 кгс (HV10)) | По Супер-Роквеллу, HRN (при нагрузке 15 кгс (HRN15)) | |
| 08Х13 | 0,05-0,12 | – | 750-1000 | 91-94 |
| 12Х13 | 0,05-0,12 | 750-1000 | 91-94 | |
| 20Х13 | 0,05-0,12 | 750-1100 | 91-94 | |
| 30Х13 | 0,05-0,12 | 750-1100 | 91-94 | |
| 20Х12ВНМФ | 0,05-0,12 | 800-1100 | 92-94 | |
| 08Х14МФ | 0,05-0,12 | 800-1100 | 92-94 | |
| 09Х17Н | 0,05-0,12 | 800-1100 | 92-94 | |
| 14Х17Н2 | 0,05-0,12 | 800-1000 | 92-94 | |
| 25Х17Н2Б-Ш | 0,05-0,12 | 800-1000 | 92-94 | |
| 06Х13Н7Д2 | 0,05-0,12 | 800-1000 | 92-94 | |
| 07Х16Н4Б | 0,05-0,12 | 800-1000 | 92-94 | |
| 09Х16Н4Б-Ш | 0,05-0,12 | 800-1000 | 92-94 | |
| 03Х16Н9М2 | 0,05-0,12 | 800-1100 | 92-94 | |
| 08Х16Н9М2 | 0,05-0,12 | 800-1100 | 92-94 | |
| 10Х11Н20Т3Р | 0,05-0,1 | 800-1100 | 92-94 | |
| 10Х18Н9 | 0,05-0,1 | 650-1100 | 89-94 | |
| 08Х18Н10 | 0,05-0,1 | 650-1100 | 89-94 | |
| 12Х18Н12 | 0,05-0,1 | 650-1100 | 89-94 | |
| 08Х18Н10Т | 0,05-0,1 | 650-1100 | 89-94 | |
| 12Х18Н9Т | 0,05-0,1 | 650-1100 | 89-94 | |
| 12Х18Н10Т | 0,05-0,1 | 650-1100 | 89-94 | |
| 10Х17Н13М2Т | 0,05-0,1 | 800-1100 | 92-94 | |
| 10Х17Н13М3Т | 0,05-0,1 | 800-1100 | 92-94 | |
| 31Х19Н9МВБТ | 0,05-0,1 | 800-1100 | 92-94 | |
| Марка стали | Толщина карбонитрированного слоя | Твёрдость карбонитрированного слоя | ||
| Общая толщина слоя (карбонитридная и дифузионная зона) h, мм | Толщина слоя соединений (карбонитридная зона (Е-фаза) h, мкм | По Виккерсу, НV (при нагрузке 5 кгс (HV5) или 10 кгс (HV10)) | По Супер-Роквеллу, HRN (при нагрузке 15 кгс (HRN15)) | |
| ХН35ВТ | 0,05 – 0,1 | – | 800 – 1100 | 92-94 |
| 36НХТЮ | 0,02 – 0,05 | 800 – 1100 | 92-94 | |
| Марка стали | Толщина карбонитрированного слоя | Твёрдость карбонитрированного слоя | ||
| Общая толщина слоя (карбонитридная и дифузионная зона) h, мм | Толщина слоя соединений (карбонитридная зона (Е-фаза) h, мкм | По Виккерсу, НV (при нагрузке 5 кгс (HV5) или 10 кгс (HV10)) | По Супер-Роквеллу, HRN (при нагрузке 15 кгс (HRN15)) | |
| Серый | 0,1 – 0,4 | 5-25 | 450 – 650 | 84-89 |
| Ковкий | 0,1 – 0,4 | 450 – 650 | 84-89 | |
| Высокопрочный | 0,1 – 0,4 | 450 – 650 | 84-89 | |
| Легированный чугун Сr-Ni | 0,1 – 0,4 | 450 – 650 | 84-89 | |
РЕКОМЕНДАЦИИ
ПО ИЗМЕРЕНИЮ ТВЁРДОСТИ
КАРБОНИТРИРОВАННОГО СЛОЯ
Recommendations for control of the depth of the carbonitrided layer
The total depth of the carbonitrided layer of the parts is controlled on an etched section (4% nitric acid solution in ethyl alcohol) using an optical microscope. The section must be made from a reference sample. The layer depth is the value of the increased etching zone from the surface of the sample to the main structure of the core.
In complex cases, the total depth of the carbonitrided layer of the parts can be determined by the distribution of microhardness in the cross section of the reference sample. Microhardness is measured at a distance of no more than 0.05 mm along three tracks using a PMT-3 device with a load of 50 g. In this case, the layer depth is the distance from the surface to the hardness values, which exceed the core hardness value by (30 – 50) HV.
Note. If the data differs when determining the depth of the carbonitrided layer using the specified methods, preference is given to the microhardness measurement method.
The depth of the compound layer (e-phase) is controlled on an etched section using an optical microscope. The depth of the e-phase layer is taken to be the length of the unetched zone obtained on the transverse section.
Analogues of the carbonitriding process
Due to their effectiveness, these strengthening methods have been highly appreciated in all industrially developed countries.
Carbonitriding is an analogue of the widely used technologies of strengthening parts in molten salts throughout the world.
TUFFTRIDE
TENIFER process
QPQ
ARCOR
MELONITE process
DYNA-BLUE
BLACKNITRIDE
Sulfinuz
Sursulf
KQ-500
SBN
Nitride
Nutride
Meli 1
Isonite
Palsonite
FNC process
Analogues of the carbonitriding process
Due to their effectiveness, these strengthening methods have been highly appreciated in all industrially developed countries.
Carbonitriding is an analogue of the widely used technologies of strengthening parts in molten salts throughout the world.
TUFFTRIDE
TENIFER process
QPQ
ARCOR
MELONITE process
DYNA-BLUE
BLACKNITRIDE
Sulfinuz
Sursulf
KQ-500
SBN
Nitride
Nutride
Meli 1
Isonite
Palsonite
FNC process
QUESTIONS AND ANSWERS
What is carbonitriding?
Carbonitriding is a type of chemical-thermal treatment for surface hardening of steel and cast iron parts, which consists of simultaneously saturating their surface with nitrogen and carbon. Carbonitriding technology is most often used instead of traditional nitriding. Carbonitriding can also be recommended as an alternative to the processes of carburizing, nitrocarburizing, surface hardening with high-frequency current, and galvanic chromium plating.
Why is the process called "carbonitration"?
The name “carbonitration” was established by the developer of the process. It means simultaneous saturation of the surface of steel products mainly with nitrogen and to a lesser extent with carbon. Unlike nitrocarburizing, carbonitration is carried out at significantly lower temperatures.
What is the difference between the carbonitriding process and the gas nitriding process?
The carbonitriding process is carried out in a salt melt, and the main diffusing elements are nitrogen and carbon. In gas nitriding, such an element is nitrogen, formed during the dissociation of ammonia. This significantly affects the structure of the diffusion layer. In gas nitriding, nitride phases are formed, and in carbonitriding, carbonitride phases.
What are the characteristics of the diffusion layer after carbonitriding and after gas nitriding?
The surface hardness and layer thickness for each specific material are practically the same, but due to the structural features of the surface zone, the carbonitrided layer has a wear resistance that is 2 times higher. The fatigue strength and contact endurance characteristics are equivalent.
How long does the carbonitriding process take?
The duration of holding of parts during processing by the carbonitriding method is 5 or more times shorter than during gas nitriding (with the same requirements for the thickness of the hardened layer). The heating time of parts is significantly reduced, and cooling can be carried out immediately after unloading the parts from the bath in air, water or oil. Sequence and approximate duration of operations:
What equipment is used for the carbonitriding process?
To carry out the carbonitriding process, a shaft electric furnace-bath with a crucible made of titanium alloy is used, preventing contamination of the salt melt and significantly improving the quality of the hardened layer. Before carbonitriding, parts are necessarily preheated to 300-350 ° C in a separate furnace. To clean the parts from adhering salt, rinsing baths with hot or cold water are used.
What salts are used for baths?
For the fusing of the bath, salts synthesized from ammonium carbon compounds (melamine, melon, dicyandiamide) are used.
In what condition should parts be delivered for carbonitriding?
- Carbonitriding is a finishing process, so the parts must arrive in a final mechanically processed condition. For the most critical parts (with precise fit dimensions and a high roughness class), it is recommended to leave an allowance of 0.01-0.03 mm (determined individually in each specific case), for polishing (honing) to obtain the specified roughness and dimensional accuracy. Other parts can be used without additional mechanical processing. It is not recommended to remove the carbonitrided layer by grinding.
- To ensure sufficient strength and toughness of the core, the parts in the blank state must be subjected to hardening with high tempering (thermal improvement) – for alloy steels, normalization – for carbon steels.
- To avoid warping (deformation) during carbonitriding, complex-shaped parts, such as shafts with a large number of steps, large-diameter rings with deep grooves, thin-walled bushings, etc., after rough machining, it is recommended to subject them to tempering to stabilize the dimensions. After tempering, the parts undergo final machining (grinding) and are sent for carbonitriding.
Carbonitriding, nicotriding and liquid carbonitriding
are important methods of thermochemical treatment of steel, which are used to improve its mechanical properties and wear resistance. Let’s consider each method in more detail.
Carbonitriding is a process in which the surface layer of steel is enriched with carbon and nitrogen. As a result of the treatment, there is an increase in hardness, wear resistance and improvement in the bending and fatigue properties of the material. Carbonitriding is used to treat mechanical parts such as shafts, gears, cogwheels, which operate under increased loads.
Nicotriding is a process of saturating the surface layer of steel with nitrogen. This method increases the hardness of the material, as well as increases its resistance to wear and corrosion. Nicotriding is used to treat various mechanical parts that operate under increased loads and friction, such as cranks, pistons, cylinders, etc. Liquid carbonitriding is one of the most effective methods of surface hardening of metal, in which the surface layer is saturated with carbon in a liquid medium. This process allows you to obtain a material with high hardness, wear resistance and corrosion resistance. Liquid carbonitriding is used to treat machine parts and equipment that are subject to high loads and friction, such as crankshafts, gears, pinions, etc.
Karbaz provides services for carbonitriding, nicotriding and liquid carbonitriding of steel. We use the most modern equipment and high-quality materials to provide our customers with optimal results. When you contact us, you can be sure