Process family
LPC, vacuum carburizing, acetylene LPC, boost-diffusion cycles, low-pressure carbonitriding context and LPC + high-pressure gas quenching (HPGQ) equipment chains.
HPGQ term
HPGQ means high-pressure gas quenching. In the LPC context it means that after low-pressure carburizing / vacuum carburizing the load is quenched by a high-pressure gas flow instead of conventional oil quenching.
Ukrainian wording: цементація при низькому тиску з подальшим високонапірним газовим гартуванням. Russian wording: цементация при низком давлении с последующей закалкой газом высокого давления.
The term is useful, but not always immediately recognizable outside vacuum heat-treatment circles, so it should be expanded on first use.
Positioning
LPC / low-pressure carburizing is treated as a separate vacuum thermochemical technology, instead of a minor note inside generic heat treatment. It belongs in the same evidence system as plasma nitriding, duplex treatment and vacuum thermal processing.
Target results
Hard case, wear and fatigue resistance, clean surface, lower oxidation, reduced distortion and controlled surface carbon / case-depth profile.
Applications
Automotive drivetrain, gears, shafts, synchronizers, railway and heavy transport transmissions, aerospace actuators, heat-treatment service centers and R&D pilot production.
Equipment and RFQ checks
| Topic | What should be specified |
|---|---|
| Furnace architecture | Single/multi-chamber LPC furnace, heating method, graphite/metal hot zone, load geometry, handling, HPGQ or oil-quench module. |
| Gas and cycle | Hydrocarbon gas, boost/diffusion sequence, pressure range, flow stability, gas distribution, recipe repeatability. |
| Quality control | Case depth, carbon profile, hardness profile, microstructure, retained austenite, distortion, surface cleanliness and test-coupon plan. |
| Materials | Case-hardening steels, high-alloy steels, component geometry, risk of carbide formation and quench sensitivity. |