vacuum carburizing (LPC)
what is low pressure carburizing?
The low pressure carburizing (LPC) process, also known as vacuum carburizing, is a thermochemical heat treatment in which steel parts are heated to temperatures usually in the range of 900 – 1000 °C and placed in a carburizing atmosphere. It is an alternative technology to traditional carburizing in a protective gas (atmospheric).
Low pressure carburizing offers a clean and modern approach to carburizing. This heat treatment requires real precision and allows for minimal deformation of the original component during carburizing, but always in accordance with the existing residual stress state of the component.
low pressure carburizing process
The purpose of carburizing is to enrich the surface layer with carbon and thus increase hardness and abrasion resistance while maintaining a malleable core. Immediately after carburizing, hardening and tempering is usually carried out. In contrast to traditional carburizing, vacuum carburizing has a number of advantages resulting from both the carrier gases used – C2H2/acetylene – and the environment in which it is carried out – a vacuum furnace. It is environmentally friendly – no CO2 emissions from the process.
advantages of low pressure carburizing
Tool steel in particular benefits from low-pressure carburizing, as the process results in very wear-resistant surfaces. This is ideal for toolmaking.
The most important advantages are:
- No oxidation at the grain boundaries
- Narrower tolerance range of case-hardening depth – lower scattering of results
- Stability and repeatability of results
- Accurate carburizing of narrow bores, including blind holes
- Minimization of quenching deformations – resulting from the use of gas as a quenching medium, although oil quenching is also possible.
- Increased production efficiency due to the ability to run processes at higher than conventional temperatures, i.e. 980 °C and higher
- Clean surface (silver-metallic), no oxidation
- Environmentally friendly – no CO2 emissions from the process
suitable steels for low pressure carburizing
Higher alloyed case-hardening steels that still have a sufficient cooling rate during nitrogen quenching. Less suitable for unalloyed and low-alloy steels.
fields of application
Transmission gears and shafts, particularly in the automotive sector, as well as for industrial transmissions and similar applications. High-pressure injection components for combustion engines. Bearing shells and rings for plain and ball bearings.
benefits from our services, from the idea to series production
- Developing individual innovations
- Clarify detailed questions
- Support from the idea to series production
- First-class support
- Highest quality – whether small or large series
- Certified according to DIN EN ISO 9001:2015, VDA 6.1:2016 and ISO 13485:2016
frequently asked questions – low pressure carburizing
How does low pressure carburizing differ from other heat treatment processes?
Low pressure carburizing is a process in a vacuum furnace, i.e. carburization does not take place in an atmosphere containing carbon (endogas) with oxygen. As a result, there is no edge oxidation in low-pressure carburizing.
How long does the low pressure carburizing process usually take?
There is no rule here. The process time depends on the treatment temperature, the component geometry and the carburization depth to be achieved.
Are there any special post-treatments that are required after low-pressure carburizing?
Special post-treatments are not required. In the case of quenching under nitrogen, a final cleaning is required.
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