“The DFM feedback was incredibly detailed and helped us reduce cycle time by 15%. The transparency in the injection molding process is unmatched.”
Distortion-Controlled Carburizing Case-Hardening Solutions
Overcoming inherent thermal treatment challenges such as macro-distortion and inconsistent case depths across complex geometries, we engineer highly uniform surface hardness profiles without compromising core ductility. By dynamically modulating atmospheric carbon potential and deploying optimized, multi-stage quenching cycles, our workflows translate raw steel alloy vulnerabilities into exceptional wear resistance and high-cycle fatigue strength. Backed by our rigorous IATF 16949-certified quality framework, we maintain a precision-controlled effective case depth across all production batches, thereby preventing premature subsurface delamination and ensuring absolute dimensional stability for mission-critical robotics and automation components.
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SURFACE ENGINEERING
What is Carburizing & The Science Behind the Case Hardening
Carburizing is a specialized thermochemical case-hardening process that diffuses carbon into the surface of low-carbon steel components at elevated temperatures. Unlike through-hardening, which can leave parts completely brittle, carburizing creates a highly wear-resistant, high-carbon surface layer (the case) while maintaining a tough, ductile, low-carbon core. This dual-property structure prevents catastrophic failure under heavy dynamic impact and guarantees long-term fatigue resistance, making it an indispensable heat treatment for high-stress robotics gears, aviation actuators, and durable medical device components.
Pre-Treatment & Selective Masking
Raw machined or stamped components undergo rigorous alkaline cleaning to remove all residual manufacturing oils and contaminants. For parts requiring localized hardening, precision masking techniques such as copper plating or specialized stop-off compounds are applied to specific areas. This ensures targeted carbon absorption, preserving maximum ductility and machinability in critical features like internal threads or areas intended for post-process welding.
Atmospheric Carbon Diffusion
The prepared parts are loaded into advanced atmospheric control furnaces and heated to austenitic temperatures (typically 850°C to 950°C) within a tightly regulated carbon-rich environment. By meticulously controlling the carbon potential and diffusion time, carbon atoms are driven deep into the steel substrate. Our automated furnace systems continuously monitor these thermal variables to guarantee uniform case depth distribution, even across the complex geometries of custom stamped and milled parts.
Precision Quenching & Tempering
To lock in the extreme surface hardness, the carbon-enriched components are rapidly quenched in highly controlled oil or polymer mediums, transforming the outer layer into wear-resistant martensite. Immediately following the quench, the parts are systematically tempered at lower temperatures. This critical thermal stress-relief step eliminates quenching-induced brittleness, perfectly balancing an ultra-hard exterior with a highly shock-absorbing inner core.
Metallurgical Quality Assurance
Every completed batch is subjected to rigorous destructive and non-destructive inspection protocols. Effective case depth and surface hardness (HRC/HV) are precisely verified using advanced microhardness testers and cross-sectional microstructural analysis. By closely monitoring for optimal martensitic transformation and preventing excessive retained austenite, we ensure every component strictly adheres to your exact engineering specifications and stringent aerospace or medical industry standards.
Surface engineering isn’t just a finishing touch—it’s a critical performance factor. You don't just need a vendor; you need a partner who masters the technical nuances of both metal and plastic. Discover our tailored solutions designed to meet your industry's most rigorous standards.
CAPABILITY DATA
Engineered Carburizing Specifications & Capabilities
Kravzik provides rigorous atmospheric and thermal control to ensure consistent, repeatable case-hardening results. Our carburizing capabilities are calibrated to meet the tight metallurgical tolerances and high-wear performance criteria required for precision metal stamping components, durable medical instruments, and automated robotic drive systems.
Request DFM EvaluationCarburizing Processes
Gas Carburizing (Endothermic Atmosphere) and Low-Pressure Vacuum Carburizing (LPC) designed for zero surface oxidation and minimal dimensional distortion.
Effective Case Depth (ECD)
0.1mm – 3.0mm (0.004″ – 0.118″) — precisely controlled via advanced diffusion cycles to guarantee the optimal ratio of hard outer shell to ductile core.
Surface Hardness Range
58 – 64 Rockwell C (HRC) — delivering exceptional wear and abrasion resistance, significantly extending the operational lifespan of high-friction components.
Core Toughness (Hardness)
30 – 45 Rockwell C (HRC) — retaining essential shock-absorbing characteristics within the base metal to prevent brittle fracture under heavy dynamic loads.
Compatible Substrates
Optimized for low-carbon and alloy steels, including AISI 1018, 1020, 8620, 9310, and 12L14, tailored for stringent medical and automation engineering standards.
Furnace Capacity & Part Dimensions
Accommodating high-volume precision micro-stampings up to large machined assemblies (Max Processing Envelope: 1200mm x 800mm x 800mm / Max Batch Weight: 500kg).
ALLOY VERSATILITY
Compatible Material Substrates for Carburizing
The ultimate effectiveness of a case-hardened profile relies fundamentally on the initial carbon content and alloying elements of the base metal. Kravzik engineers meticulously adjust carbon potential (CP) algorithms and thermal diffusion cycles to accommodate the specific metallurgical properties of various low-carbon and alloy steels utilized in critical medical device, robotics, and automation sectors.
Low-Carbon Steel (AISI 1018, 1020, SPCC)
The industry standard for custom automation brackets, specialized equipment housings, and structural chassis. Because these grades lack significant alloying elements, we optimize the endothermic gas atmosphere to ensure deep, rapid carbon penetration. This is followed by aggressive, tightly agitated quenching protocols to achieve maximum martensitic transformation and uniform surface hardness without localized soft spots.
Low-Carbon Alloy Steel (AISI 8620, 4120)
Frequently specified for high-stress robotics gears, heavy-duty actuators, and load-bearing cam mechanisms. The presence of nickel, chromium, and molybdenum drastically improves core hardenability. Processing these alloys utilizes our precise low-pressure vacuum carburizing (LPC) protocols to completely eliminate intergranular oxidation (IGO), ensuring superior fatigue strength and mitigating dimensional distortion on complex machined profiles.
High-Alloy Carburizing Steel (AISI 9310, 3310)
Essential for critical aviation actuators, high-speed medical centrifuge components, and extreme-load transmission shafts. These premium grades demand extended, meticulously controlled carbon diffusion cycles. We integrate specialized sub-zero (cryogenic) treatments immediately post-quench to fully transform retained austenite into hard martensite, maximizing wear resistance and guaranteeing long-term dimensional stability under extreme operational stress.
Free-Machining Steel (AISI 12L14, 1117)
Ideal for precision CNC-machined medical fittings, complex threaded fasteners, and custom automation alignment pins. While excellent for machinability, added sulfur or lead can complicate thermal processing. We strictly regulate the atmospheric potential and employ tailored, lower-temperature tempering cycles to prevent core embrittlement and surface micro-cracking, delivering a highly wear-resistant case while preserving the structural integrity of delicate internal threads.
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PROCESS GUIDELINES
Essential Design Guidelines & Process Limitations
Proactive design optimization prevents heat-treatment failure and ensures your components meet exact engineering specifications. Consider these critical metallurgical and dimensional factors before finalizing your CAD models for the carburizing process.
Carburizing and the subsequent quenching process typically cause a slight volume expansion due to the diffusion of carbon atoms and the transformation of austenite to martensite. For precision-fit components like gears or spindles, Kravzik engineers recommend incorporating a post-heat treatment grinding allowance (typically 0.15mm to 0.25mm). This ensures that the final critical dimensions are achieved while removing any minor surface oxidation or “white layer” that may occur during the thermal cycle.
Exposing parts to temperatures between 850°C and 950°C followed by rapid quenching introduces significant thermal and transformational stress. Non-symmetrical parts or components with extreme thickness variations are prone to warping or “potato-chipping.” To mitigate this, we advise designing parts with uniform cross-sections and generous radii in corners to distribute stress evenly. For high-precision parts, we utilize custom quenching fixtures to maintain geometric integrity.
In many applications, certain features—such as internal threads, thin flanges, or areas intended for post-process welding—must remain soft and ductile to prevent brittle fracture. We achieve this through selective masking using copper plating or specialized ceramic stop-off compounds to block carbon diffusion. Please ensure your technical drawings explicitly define these “Keep Soft” zones so our team can apply precise masking before the parts enter the atmospheric furnace.
Sharp corners and thin edges tend to absorb carbon from multiple sides simultaneously, leading to “over-carburization” or brittle peaks that are prone to chipping under load. We recommend a minimum radius or chamfer of 0.5mm on all external edges. This design adjustment ensures a uniform case depth profile across the entire part geometry, preventing localized carbon concentration and maintaining the structural durability of the component’s profile.
VISUAL EXCELLENCE
Data-Driven Showcase: Engineered Case Hardening Profiles
The ultimate wear resistance, fatigue strength, and dimensional stability of a case-hardened component are dictated by the specific carbon diffusion method and quenching medium. Explore our standard carburizing profiles to identify the precise metallurgical specifications and structural integrity required for your specific engineering assembly.
CONTROLLED ATMOSPHERE
Gas Carburizing (Endothermic)
Utilizing a precisely regulated endothermic gas environment, this process delivers a robust, high-carbon case for high-volume batches of carbon steel components. It is the industry standard for ensuring consistent wear resistance and structural durability in heavy-duty automation and industrial drive systems.
Atmosphere ControlEndothermic (CO / H2 / N2)
Max Case DepthUp to 3.0 mm (0.118")
Surface Hardness58 – 62 HRC
Primary BenefitDeep carbon penetration for high-load durability
Ideal ForHeavy-duty gears, drive sprockets, industrial pivot pins
PRECISION THERMAL
Low-Pressure Carburizing (LPC)
Performed in a high-vacuum furnace with pulsed acetylene injection, LPC eliminates "intergranular oxidation" (IGO) and guarantees the highest possible fatigue strength. This method is essential for precision medical and aerospace components with complex geometries that require absolute surface cleanliness.
EnvironmentLow-Pressure Vacuum (<10 mbar)
Dimensional StabilitySuperior (Mitigates post-quench warping)
Surface FinishBright / Clean (No descaling required)
Primary BenefitExceptional fatigue life & zero surface decarburization
Ideal ForRobotic actuators, surgical instruments, aerospace splines
SPECIALTY HARDENING
High-Hardness Carbonitriding
By introducing ammonia into the carburizing atmosphere, we infuse both carbon and nitrogen into the substrate. This creates a surface layer that is harder than standard carburizing and significantly more resistant to temper-softening, making it ideal for high-friction, precision-stamped parts.
Infusion ElementsCarbon + Nitrogen (Dual-Diffusion)
Process Temp790°C – 845°C (Lower thermal stress)
Hardness RetentionHigh (Maintains integrity up to 200°C)
Primary BenefitMaximum surface hardness on low-alloy steels
Ideal ForPrecision thin-walled stampings, fasteners, wear plates
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SERVICES LIBRARY
Explore Other Industrial Surface Treatment & Finishing Services Available
PVD Coating
Stop tool wear causing costly downtime. Our 3500HV PVD coatings extend component life by 1000% for extreme durability.
Aluminum Anodizing Services
Eliminate galling in your robotic joints. Our hardcoat aluminum anodizing achieves a tough 70 HRC surface.
Nitriding
Forget brittle surfaces and dimensional warping. Kravzik delivers 1200 HV surface hardness while maintaining absolute ±5µm geometric precision.
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TECHNICAL REFERENCE
Frequently Asked Questions
Answers to common questions regarding precision, tooling, materials, and our integrated molding capabilities.
We utilize precise carbon potential control and multi-stage quenching to create a wear-resistant martensitic case while maintaining a shock-absorbing low-carbon core for high-impact robotics and automation applications.
Our facility employs low-pressure vacuum carburizing (LPC) and customized quenching fixtures to strictly manage thermal stresses, ensuring final part geometries remain within your specified engineering tolerances.
We specialize in AISI 1018, 8620, and 9310 alloys, tailoring our atmospheric diffusion cycles to the specific metallurgical properties of each grade for optimal case-to-core hardness ratios.
Yes, we utilize advanced copper plating or ceramic stop-off compounds to mask areas like internal threads, ensuring they remain ductile and machinable for secondary assembly or welding operations.
Operating under IATF 16949 standards, we perform microhardness testing and cross-sectional analysis on every batch, providing full material traceability and certified metallurgical process documentation for every shipment.
We typically recommend a post-heat treatment allowance of 0.15mm to 0.25mm to account for minor volume growth and to achieve final micron-level tolerances during the finishing stage.
Vacuum carburizing (LPC) is ideal for complex medical or robotic parts requiring zero surface oxidation, deep blind-hole penetration, and superior fatigue resistance without any intergranular oxidation risks.
Our versatile furnace envelopes accommodate everything from precision micro-components to large structural parts up to 1200mm, supporting both rapid prototyping and high-volume global production scales.
Still have questions?
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