Steel Quality Determination Time: At the Melting Furnace
In steelmaking, the critical moment that determines quality is when the molten steel remains in the furnace—before casting. Once the steel is cast and solidified, any deviation in chemical composition becomes scrap that cannot be salvaged. This is especially true for high-precision steel grades such as carbon steels 35# and 45#, structural alloy steels, tool steels, bearing steels, stainless steels, and special-purpose steels. A mere 0.1% difference in carbon content between two grades can completely alter their mechanical properties—from hardness and tensile strength to wear resistance.
The current carbon-silicon analyzer only measures solid samples, not liquid ones. This gap leaves steel mills without a tool to monitor C and S content right at the furnace inlet—before tapping.
The Changyouyi (CYY) Arc Infrared Carbon-Sulfur Analyzer, capable of analyzing external carbon and sulfur in CYY-TL5 (CYY-TL5, features a fully automated workflow: Although housed in the lab, it delivers results in just 35 seconds per sample. Including sampling, water quenching, grinding, and weighing (approximately 3 to 5 minutes total), the entire process—from operator loading to final C% and S% results—takes only 3 to 5 minutes. This speed enables precise composition adjustments before steel casting.
How It Works: From Steel Mold to Result in 35 Seconds
CYY-TL5 uses the arc combustion and infrared absorption method, complying with GB/T 223.69-2008 and GB/T 223.68-1997.
Pre-Production Detail Inspection Process
Step 1: Take steel sample using a concrete core drill, then quench rapidly in water -- approx. 30 seconds Step 2: Crush/grind the sample into powder or fine pieces -- approx. 1 to 2 minutes Step 3: Weigh the sample (approx. 0.5g for steel, approx. 0.2g for cast iron) on balance 0.0001g -- approx. 30 seconds Step 4: Mix with flux: silicon-molybdenum approx. 0.3g + tin chips approx. 0.3g + pure iron approx. 0.3 to 0.5g -- approx. 30 seconds Step 5: Place in arc furnace and click "Start Analysis" Step {17]: Ignition + gas flow through outer chamber + red detector -- approx. 35 seconds Step 7: Software displays C% and S%, generate report -- approx. 10 seconds Total: From sampling to result display -- approx. 3 to 5 minutes
How to Detect External Errors
CO2 absorbs strongly in the far-infrared region at 4.26 µm, and SO2 absorbs at 7.35 µm. The pyroelectric detector ((LiTaO3) operates at room temperature with broad and stable response, converting optical signals into analog voltage, which is then digitized via an A/D converter (8000 samples/sec, ICL7135 chip) for processing by the computer.
The Lambert-Beer equation describes the absorption process: I = I0 × exp(-aPL). Where: I0 = incident light intensity, I = transmitted light intensity, a = absorption coefficient, P = partial pressure of gas, L = absorption path length.
Software for calculating the area under the curve, applying calibration factors, subtracting blank values, and normalizing by sample weight to yield %C and %S.
Technical Review CYY-TL5 -- Optimize Pre-Production Testing
Carbon (C) content: 0.005% - 10.0000% (expandable per request) Sulfur (S) content: 0.0005% - 0.3500% (expandable per request) Repeatability (RSD): C ≤ 0.5%, S ≤ 1.5% Analysis time: 30-60 seconds (fast mode pre-heating interval: 35s) Weighing capacity: 0-10g, resolution: 0.0001g Power supply: AC 220V ±5%, 50Hz ±2%, 3KVA; ground resistance ≤ 4 Ohm During analysis: O₂ ≥ 99.5% (for carbon/sulfur samples, use pure oxygen ≥ 99.99%); outlet pressure: 0.08MPa (cylinder: >3MPa,) Gas flow rate: 1.2-2.0 L/min Ambient temperature: 15-30°C, humidity ≤ 60% Accuracy: Complies with GB/T 223.69-2008, GB/T 223.68-1997
Steel Type-Specific Pre-Loose Inspection Tool
- Thep Carbon 35# va 45# -- Exact Control 0.1% C
- 35#: C 0.32-0.40%, S ≤0.035%
- 45#: C 0.42-0.50%, S ≤0.035%
- The carbon difference is limited to 0.1%. With pre-tap sampling and analysis within 3 to 5 minutes, operators can measure the actual carbon percentage (C%) of the molten steel in the furnace. If C is low, add ferro-carbon (carbon booster). If C is high, add dilution steel or extend oxygen blowing time. Only when the C% falls within the target range will the steel be cast into molds.
- Thep Hop Kim Ket Cau (SCM435, 40Cr, 42CrMo)
- These steel grades require C in the range of 0.33-0.43% plus a specified amount of Cr/Mo. CYY-TL5 Control C and S before the furnace; high S (> 0.035%) causes hot shortness during forging/rolling. Detect S before the furnace → add CaSi or perform desulfurization treatment before tapping.
- Thep Công Cụ (Thép Dụng Cụ: SKD11, H13, D2)
- Tool steel has high hardness (0.8-2.0%) and very low softening temperature (<0.02%). CYY-TL5 extends the hardening depth to 10% -- a key factor in tool steel performance. Verify S before quenching to prevent cracking and residual stress after heat treatment.
- Thep O Bi (Bearing Steel: GCr15, SUJ2)
- GCr15 carbon content 0.95-1.05% with S ≤ 0.020%. Carbon deviation directly affects hardness uniformity and service life. Perform rapid pre-check + adjustment to ensure consistent compliance.
- Thep Khong Gi (Stainless Steel: 304, 316, 430)
- Low C content in ultra-low carbon stainless steel (<0.08% for 304L), S must still be controlled at <0.03%). CYY-TL5 to 0.0005% S range is sufficient for ultra-low carbon stainless steel. Verify S meets standards before heat treatment to prevent cracking during machining.
- Thep Dac Chung (Special Steel: Heat-resistant, Wear-resistant)
- High-temperature and abrasion-resistant steel grades have complex compositions. CYY-TL5 controls C and S—the two primary elements before the converter—to establish an accurate foundation for subsequent alloying.
So Sanh CYY-TL5 Voi May Quang Pho Phat Xa (Spark OES) -- Loi The 1/5 Gia
Device specifications: CYY-TL5 within 1/5 OES range (more economical than listed, compared to Vietnam market 2024-2025) Time/sample: CYY-TL5 within 35 seconds (analysis) + 3-5 minutes (sampling) Carbon accuracy: High (meets GB/T, RSD <=0.5%) Sulfur accuracy: High (RSD <=1.5%, low detection limit for sulfur) Element coverage: CYY-TL5 only C and S (specialized); OES covers multiple elements (Fe, C, S, Mn, Si, Cr, Ni...) Operating cost: CYY-TL5 Low (requires only oxygen + flux); OES Medium (high-purity argon required) Maintenance: CYY-TL5 Simple (clean burner head, replace reagents); OES Complex (electrodes, optical system calibration) Pre-furnace compatibility: CYY-TL5 Yes -- sufficiently fast, sufficiently accurate
Strategic summary: CYY-TL5 cannot replace OES for multi-element analysis, but it is the most cost-effective solution for pre-tap control of C and S—the two elements that determine steel grade. The plant can use CYY-TL5 for rapid pre-tap checks and steel adjustment; if available, use OES or CYY-TL5 plus supplementary chemical analysis for final product inspection before shipment. Total investment costs only about 1/5 compared to purchasing a standalone OES (based on average market quotes in Vietnam from 2024 to 2025, referencing standards GB/T 223.69-2008 and ASTM E1019).
Pre-Melt Inspection Process: From Sampling to Steel Decision
Load steel into furnace --> Operator takes sample (30 seconds) --> Sample cools inside vessel --> Cooling + powder addition (1-2 minutes) --> Add powder --> Dry + add fluxing agent (1 minutes) --> Ready for analysis --> Place in furnace CYY-TL5,, press F1 (35 seconds) --> Display C% and S% results --> Evaluate compliance. If compliant --> Release steel --> Mold/Rod rotation. If non-compliant --> Adjust composition (increase carbon/remove sulfur/dilute) --> Retake sample (additional 3-5 minutes) --> Re-evaluate. If compliant --> Release steel.
The entire pre-hole adjustment cycle can be completed in 5 to 10 minutes—much faster than sending samples externally (3-7 days) and more cost-effective than OES (based on average market reference prices).
Product Quality Inspection: Second Layer Protection
After steel production and processing into finished products, CYY-TL5 continues to play a critical role in final quality inspection before delivery: Select representative samples from the finished goods (bars, sheets, pipes) → Analyze C% and S% using CYY-TL5 → Compare against customer standards → Generate reports directly from the software (available in English/Vietnamese) → Attach COA (Certificate of Analysis) with shipment. This is the second layer of protection—ensuring any minor deviations can be corrected before shipment, guaranteeing that all products meet specifications when they reach the customer.
System Settings CYY-TL5
LO Dot Ho Quang Mau x1 Infrared Analysis Module x1 Computer + Software + Security Key x1 Monitor x1 Inkjet Printer x1 Electronic Scale 0.0001g x1 Accessories + Cables + Consumables x1 set User Manual + Certificate x1 set
Hieu Chuan Truoc Lo: Maintain Trust Before Starting Work
Harsh pre-heat conditions (high temperature, freezing) require CYY-TL5 to perform either a new calibration or daily calibration: Select 3 to 4 national standard samples with C/S content close to the currently produced steel --> Perform continuous analysis, select 2 to 3 results with good repeatability --> Go to the Calibration Coefficient interface --> Enter the standard value --> Calibrate Carbon/Calibrate Sulfur --> Save calibration --> Record the new coefficient and start the pre-heat inspection batch.
Previous step: Using a standard color with higher saturation than the target color results in more accurate outcomes for low-saturation colors.
Scheduled Maintenance for Pre-Lo Environment
High-temperature furnace preheater, CYY-TL5 needs: Every 24 month: Clean dust chamber filter. Every 60 months: Remove and clean the filter with a steel brush; recheck for leaks. Daily: Replace the air filter when 1/3 is dirty; clean the arc furnace filter. Quartz tube + rubber ring: Inspect regularly; replace if hardened to prevent leaks.
Why Choose Changyouyi (CYY)?
Nanjing Changyouyi Analytical Instrument Co., Ltd. – Your expert in quality and metal analysis equipment: CE Certified with English interface, serving the global market. Specialized in Vietnam: we understand steel mill needs before you invest. Competitive pricing – approximately 1/5 of OES cost (market reference 2024-2025), with fast ROI. Technical support from our experienced engineering team. Integrated solutions: CYY-W330/W6{5] spectrometers + CYY-LK2/LK7 carbon-silicon analyzers (for molten iron) + CYY-TL5 carbon-sulfur analyzers (for molten steel) = complete pre-investment solution.
Contact to get a quote for CYY-TL5 pre-loan inspection
Email: russ.gu77@gmail.com Hotline: +86 18795833542 Address: NO.8 HUASHAN RD., DEVELOPMENT ZONE, GAOCHUN, NANJING, CHINA
Get a quote today — deploy the pre-loose rapid inspection system within weeks to save costs and improve your steel bar quality!