What is the Chinese equivalent of NiCr 40/20 or Ni40Cr20?

GB Cr20Ni35. NiCr 40/20 has Ni ≥37.0%, Cr 18–22%, Si 1.8–3.0% and resistivity ≈1.05 μΩ·m; GB Cr20Ni35 has Ni 34.0–37.0%, Cr 18.0–21.0%, Si 1.00–3.00% and resistivity 1.04 μΩ·m. The two overlap across the composition range.

Is there a grade called Cr20Ni40 in the Chinese standard?

No. GB/T 1234 does not define Cr20Ni40. Some Chinese suppliers use it as a commercial name, but the standardised grade is Cr20Ni35.

Does NiCr 40/20 have an ASTM or DIN number?

No. It has no ASTM, UNS, Werkstoff or DIN designation — it is an industry trade grade.

Can NiCr 40/20 be used in a sulphur-bearing atmosphere?

No. All nickel-chromium grades are unsuitable in sulphur atmospheres. Use FeCrAl instead.

Home › Products › Far-Infrared Gold-Plated Quartz Tubes

Far-Infrared Gold-Plated Quartz Tubes

Short answer: we supply gold-plated quartz infrared emitter tubes for drying, curing and pre-heating tunnels, in watt densities matched to the line speed and the product.

When output drops but the gold looks fine, it is devitrification
Quartz starts to crystallise (devitrify) above about 1,100 °C, and contamination on the surface accelerates it. The crystallised layer scatters infrared instead of transmitting it, so the tube runs hotter and output falls. If a tube loses output with an intact gold layer, check the sheath temperature and the air velocity around it — low airflow lets the tube overheat.

1. Construction

Item	Typical	Note
Tube OD	φ10 – 25 mm	Larger OD gives more power per unit length
Length	200 – 3,000 mm	Made to order
Watt density	10 – 40 W/cm²	Higher needs better airflow
Gold coating	Single or double sided	Reflects radiation back toward the product
End fittings	Ceramic cap, wire leads, terminals	Sealing affects life in humid lines

2. What shortens tube life

Low airflow — the tube overheats, which accelerates devitrification.
Surface contamination — dust and oil mist on the tube promote crystallisation. Clean monthly.
Quartz grade — high-purity quartz (OH < 5 ppm) devitrifies later, at a price premium.
Mechanical stress — clamping a tube rigidly during thermal expansion cracks it.

3. Please confirm these 4 points before ordering

Required power and tube length — and the line speed, which sets the watt density.
Air velocity around the tube — if the fan runs continuously including idle periods, say so.
Product and distance — determines whether single or double-sided gold is appropriate.
Environment — dust, oil mist or humidity all affect the quartz grade choice.

Need a quotation?

Send grade, form, size with tolerance and quantity — we reply within one working day (GMT+8).

WhatsApp +86 180 6103 5177 Enquiry form

About Taizhou Aolante Alloy

Taizhou Aolante Alloy Materials Co., Ltd. was founded in 2010 and is a source manufacturer of electric heating alloys, precision resistance alloys and furnace accessories. Production base in Taixing, Taizhou, Jiangsu, approximately 20,000 m², 48+ pieces of melting, forging, rolling, drawing, heat-treatment and testing equipment, 200+ staff, annual capacity about 7,500 tonnes.

Our range covers heating wire and strip, heating cable, wide thin strip, radiant tubes, heat-resistant steel, conveyor belts, superalloys, industrial furnaces, thermocouples, refractory insulation, heating tubes, CuNi/MnCu alloys, far-infrared quartz tubes.

Contact: Tel +86 180 6103 5177 / +86 523 8751 8610 | Email althjcl@126.com

Grade cross-references are commercial equivalents, not a guarantee of interchangeability. Final acceptance is subject to the composition sheet agreed at order.