Non-Muffle Roller Mesh Belt Carbonitriding Furnace for Fastener Heat Treatment

Non-Muffle Roller Mesh Belt Carbonitriding Furnace is a fully automatic continuous heat treatment production line specially engineered for thin-layer surface hardening of tiny & precision steel components.

Eliminating traditional muffle structure, it adopts radiant tube direct heating + full-length roller load-bearing mesh belt conveying, matched with low-temperature carbonitriding technology. It delivers ultra-low thermal deformation, high uniform surface hardness, mirror-bright finish, stable wear & corrosion resistance, supporting non-stop 24-hour mass automated production for fastener, powder metallurgy, auto hardware and stainless steel parts.

Methanol, propane and ammonia mixed protective atmosphere is continuously injected into the muffle-free furnace chamber. Under low temperature 750–880℃, active carbon & nitrogen atoms simultaneously diffuse into workpiece surface, forming thin, compact, wear-resistant & anti-corrosion hardened case.

Equipped with multi-zone independent precise PID temperature control, oxygen probe closed-loop carbon potential regulation and integrated sealed oil quenching system, the equipment guarantees consistent case depth, zero oxidation & decarburization, controllable dimensional deformation. The full-chamber circulating airflow design enables ultra-fast atmosphere response and outstanding long-term heat treatment stability, no temperature or gas dead zones inside furnace.

1. Non-Muffle Energy-Saving Furnace Chamber

Muffle-free radiant tube direct heating realizes uniform full-chamber temperature & atmosphere distribution, high gas exchange efficiency, cutting protective gas consumption greatly. No fragile muffle spare parts, sharply lowering daily operation & maintenance cost. 

2. Full-Length Heavy-Duty Roller Conveying 

Whole furnace covered load-sharing support rollers completely solve mesh belt sagging, deviation and jamming under high temperature. Stable operation allows stacked heavy small parts production, effectively extending mesh belt service life. 

3. Precision Closed-Loop Intelligent Atmosphere & Temp Control 

Multi-zone independent PID temperature regulation + oxygen probe real-time closed-loop carbon potential control, ensuring consistent case depth & stable surface hardness across batches. One-click switching for multiple custom heat treatment recipes. 

4. Micro Positive Pressure Double Flame Curtain Anti-Oxidation 

Dual flame curtain + slight positive pressure furnace sealing isolates external air infiltration entirely. Workpieces come out mirror-bright without oxidation or decarburization, eliminating secondary pickling, grinding & polishing post-process. 

5. Waste Heat Recovery & Full Fiber Energy Saving Lining 

High aluminum full fiber energy-saving lining features fast temperature rise and low power consumption. Matching waste heat recovery & harmless waste gas treatment system, energy-saving and eco-friendly for long-run mass production. 

6. Full-Automatic PLC Intelligent Operation & Maintenance 

Full PLC touch screen interlock control, real-time operation data monitoring, automatic fault alarm and full production data traceability. Single operator can manage the whole production line to cut labor cost. 

1.Uniform & Stable Heat Treatment Quality Muffle-free full-circulation gas design eliminates temperature & atmosphere dead zones, zero soft spots & mottling on workpieces, ultra-high consistency for bulk orders. 

2.Extreme Energy Saving & Low Long-Term OPEX Muffle-free structure saves over 55% protective gas, no regular muffle replacement downtime; waste heat recovery further reduces power & gas expenditure for mass production. 

3.Heavy-Load Design for 24h Uninterrupted Mass Production Roller load-sharing support prevents mesh belt sagging, compatible with stacked small parts, supporting round-the-clock automatic continuous production. 

4.Low-Temperature Carbonitriding, Minimal Deformation 750–880℃ low-temperature co-infiltration process effectively restrains thermal deformation of thin-wall, slender, micro miniature precision components. 

5.Bright Surface, Zero Secondary Post-Processing Cost Positive pressure sealing prevents oxidation & decarburization, mirror finish directly after quenching; no pickling, buffing or polishing required, cutting downstream processing cost. 

6.Intelligent Flexible Production, Labor-Saving One-click multi-process switching, high automation level with traceable production logs; single-operator operation to reduce labor input. 

1. Fastener Raw Materials

10#, 20#, 20Cr, 40Cr, 10B21, 10B28, 45# low carbon steel, low-carbon free-cutting steel, low-alloy structural steel

2. Stainless Steel Fastener Grades

201, 304, 316, 410, 420 stainless steel

3. Standard & Precision Fasteners

Grade 8.8/10.9/12.9 bolts, flange nuts, lock nuts, self-tapping screws, drill tail screws, rivets, miniature precision fasteners, springs, spring washers

4. Powder Metallurgy Parts

Powder metallurgy gears, oil-impregnated bearings, structural components, stainless steel powder parts, copper-based friction plates, magnetic materials

5. Chain & Transmission Components

Industrial roller chains, chain sleeves, rollers, pins, chain plates, motorcycle chains, agricultural conveyor chain parts

6. Bearings & Rolling Elements

Needle rollers, miniature bearing inner & outer races, oil-impregnated bushings, cam bearings, textile & small home appliance bearings

7. Automotive Lightweight Small Hardware

Chassis fasteners, valve push rods, seat adjusting pins, small transmission gears, oil pump spools, brake precision hardware

8. Power Tools, Garden, Textile & Office Hardware

Power tool gears, ratchets, output shafts, lawn mower transmission parts, textile cams, printer gears, door lock hardware, stamped wear-resistant small stamping parts