Φ600×800mm Effective Zone Fully Automatic Intelligent Ion Nitriding Furnace for Alloy Steels and Mold Steels with Ion Nitriding and Soft Nitriding System

1. Product Overview

This vertical bell-jar single-station fully automatic intelligent ion nitriding furnace features a fourth-generation digital control system and ion nitriding pulse power supply. It can perform ion nitriding and soft nitriding of alloy steels, mold steels, and stainless steels. Equipped with touchscreen automatic control system, vacuum generation and maintenance system, and gas supply regulation system, it achieves closed-loop control of temperature, pressure, and flow rate with full-process automation. Typical applications include surface strengthening of precision workpieces such as molds, gears, and shafts.

2. Industry Challenges & Root Cause Analysis

Difficult to ensure uniform nitrided layer:Complex workpiece surface shapes (grooves, holes) cause uneven glow coverage – inconsistent layer depth and hardness. Root cause: difficult control of abnormal discharge region in gas discharge, hollow cathode effect affecting current density distribution.

Arc damage to workpiece surface:Residual oil film or contaminants on workpiece surface cause charge accumulation breakdown and instantaneous high-current arc – burning workpiece surface. Root cause: insufficient arc extinguishing speed – unable to cut current at microsecond level.

Difficult control of coupled temperature, pressure, and flow parameters:Temperature, pressure, and flow interact during ion nitriding – manual adjustment difficult to stabilize. Root cause: lack of multi-parameter closed-loop control system and PID intelligent regulation.

Poor process repeatability:Large parameter fluctuations between batches – unstable nitrided layer quality. Root cause: lack of programmed control and data recording/traceability functions.

Inadequate equipment safety protection:Misoperation risks under high voltage, vacuum, and high temperature conditions. Root cause: lack of comprehensive electrical-mechanical interlock protection and fault self-diagnosis system.

3. Solution

3.1 High-Frequency Pulse Power Supply & Fast Arc Extinguishing:Pulse power output frequency 20000Hz – square wave output – voltage 0~800V continuously adjustable – duty cycle 10-85% continuously adjustable – maximum average current 75A. Uses electromagnetic induction principle for fast arc detection – high-speed digital logic devices cut main current within 2μs – effectively protects workpiece surface. IGBT adopts Infineon brand – reliable and stable.

3.2 Three-Parameter Closed-Loop Control System:Temperature control uses Japanese Shimaden SRS13 series digital controller (PID regulation) – control accuracy ±1℃. Pressure control uses Japanese Shimaden SRS13 digital controller + frequency converter + pressure sensor – control accuracy ±1Pa. Flow control uses Japanese HORIBA S500 series mass flow meters (2 units, for nitrogen, hydrogen, etc.) – control accuracy ±0.5%. Three parameters independently closed-loop – no mutual interference.

3.3 Fully Automatic Intelligent Control Software:FX3G series programmable logic controller (32K step program memory, basic instruction processing speed 0.21μs) + Kunlun Tongtai TPC1231Ni touchscreen (12-inch, 1920×1080 resolution). Self-developed V1.0 control software (Software Copyright Registration No. 5101331) with login interface, process parameter setting, main control interface, historical curves, data reports, alarm records and other functional interfaces. Supports English interface – achieves "one-button" automatic operation.

3.4 Uniform Heating & Temperature Field Optimization:Furnace body adopts bell-jar structure – double-layer water-cooled wall + multi-channel water cooling system. Furnace chamber with 2 layers of 304 stainless steel heat shields (2mm each) + 2 layers on furnace base – ensures long-term high-temperature operation and significant energy savings. Cathode plate supported by 3 sets of high-quality cast mica – height adjustable – ensures flat surface after workpiece loading. 2 thermocouples introduced from furnace bottom plate – one for ion heating pulse power supply temperature control, one connected to alarm instrument.

3.5 Vacuum System & Pressure Closed-Loop:2X-15 rotary vane pump + GI-50 high vacuum butterfly valve – frequency converter closed-loop control. Pressure transmitter measures furnace pressure and outputs standard current signal to digital controller – PID calculation outputs signal to frequency converter – adjusts vacuum pump motor speed – maintains constant furnace pressure at process setpoint. Pressure control accuracy ±1Pa – long-term low-speed operation of vacuum pump extends service life and significantly saves energy.

3.6 Multiple Safety Interlocks & Fault Self-Diagnosis:System features over-temperature, over-pressure, thermocouple damage, water shortage, phase loss alarms (audible/visual alarm + control interface alarm) – takes corresponding protective actions such as prohibiting power-on, prohibiting heating, cutting off or resuming heating. All valves automatically close on fault. All valves are power-off shut-off type. System features fault self-diagnosis – prompts users to check and repair corresponding fault points.

4. Technical Specifications

5. Selection Guide

5.1 Recommended Scenarios

• Ion nitriding and soft nitriding of mold steels, alloy steels, stainless steels

• Precision components requiring strict nitrided layer uniformity and process repeatability

• Nitriding production lines processing larger workpieces (Φ600×800mm)

5.2 Key Selection Considerations

1. Workpiece size and load: Verify effective zone Φ600×800mm and max load 400kg

2. Process temperature requirements: Common 500-600℃, max 650℃ – confirm process temperature within range

3. Gas supply: User to provide N₂, H₂ (purity 99.9%) and compressed air (≤0.6MPa)

4. Cooling water conditions: User to provide cooling tower and pump – inlet ≤31℃, flow 20m³/h

5. Power supply: User to provide 3-phase 380V/50Hz power and 35mm² BVR copper wire (100A)

6. FAQ

Q1: How is arc damage to workpieces prevented?

A: Pulse power supply uses electromagnetic induction principle for fast arc signal detection (almost no delay) – high-speed digital logic devices cut main current within 2μs – extremely fast arc extinguishing. Compared to traditional DC power supplies, effectively protects workpiece surface from arc burns.

Q2: How is nitrided layer uniformity ensured?

A: Adjustable pulse power duty cycle (10-85%) broadens process parameter adjustment range – provides better independent controllability. Combined with three-parameter closed-loop control of temperature, pressure, and flow – improves glow coverage uniformity on complex-shaped workpieces. Hollow cathode effect is also well suppressed.

Q3: Can the equipment achieve fully automatic operation?

A: Features "one-button" automatic operation mode. Operator only needs to complete loading/unloading – system automatically starts maintenance pump and pre-evacuation pump, opens baffle valve and solenoid valve to extract vacuum, automatically activates glow discharge after reaching working pressure, automatically enters heating stage and adjusts flow/pressure/voltage/duty cycle/current per process curve, automatically shuts down and cools after holding.

Q4: How are process data recorded and traced?

A: Main control interface displays real-time operating data such as temperature, vacuum, flow, voltage – records date information for each furnace. Historical curve and data report query interface allows querying current and historical curves or parameters – data backup via network connection or external storage – reports output in EXCEL format.

Q5: What safety protection features are included?

A: Features over-temperature, over-pressure, thermocouple damage, water shortage, phase loss alarms (audible/visual + control interface) – takes corresponding protective actions such as prohibiting power-on, prohibiting heating, cutting off or resuming heating. All valves automatically close on fault. All valves are power-off shut-off type. System features fault self-diagnosis – prompts users to check and repair corresponding fault points.