Starry cobalt-based electrode

Zhide Stellite cobalt-based electrode D802: the patron saint of high temperature and high pressure valves”

In high-end industries such as power, chemicals and oil and gas, equipment components often need to operate in extreme environments of high temperature, high pressure and strong corrosion for a long time. Common steels and welding materials often fail rapidly under such conditions. D802 Co-based electrode(referred toas D802 electrode), as a classic Co-Cr-W alloy surfacing material, with its excellent high temperature resistance, excellent wear resistance and corrosion resistance, has become the first choice for repairing and strengthening the sealing surface of high temperature and high pressure valves.
This electrode adopts advanced titanium calcium coating technology, made of continuous casting Stellite 6 alloy welding wire as the core, can be AC and DC dual-use, excellent welding process performance.

🔬Product core: Why choose quality D802?

The core competitiveness of ZDE D802 lies in its unique gene **“ Cobalt alloy” **:
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Excellent high temperature resistance (* high 650℃+): This is the remarkable label of this electrode *. D802 surfacing metal is cobalt based, containing chromium 25-32%, tungsten 3-6%. The hardfacing layer can maintain stable hardness and properties at650℃, and even maintain good oxidation resistance and wear resistance at about1000℃. This makes it ideal for high temperature and high pressure valve applications.
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Excellent comprehensive mechanical properties: quality DE D802 has excellent hardness and toughness with. The hardness of the hardfacing layer can reachHRC 40. It is not only wear-resistant, but also has good impact resistance, and can withstand the severe test of hot shear blades, high-pressure pump sleeves and other parts under cold and hot alternating and impact loads.
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Perfect process adaptability:AC and DC dual-use is a highlight of the electrode, but in actual operation,DC reverse connection (DC+) effect is better. D802 arc combustion is stable, slag coverage is good, slag removal is easy, weld formation is beautiful and smooth, no obvious porosity or slag inclusion defects. In addition, the surfacing layer also has good machinability and is convenient for finishing after welding.
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Widely applicable basis: it can be welded on the surface of carbon steel, alloy steel, stainless steel and other parent metals without complex transition layer treatment, easy to operate.

📊Technical parameters and chemical composition

In order to facilitate you to quickly understand the inherent quality of this product, we have compiled the following core parameter table:

performance index	Typical values/ranges	remark
product model	D802 (EDCoCr-A-03)	Starry Co-based surfacing electrode
main component	Co (balance), Cr (25-32%), W (3-6%)	C (0.7-1.44%)
hardfacing hardness	HRC ≥ 40	ambient hardness
* High application temperature	650℃ - 1000℃	Depending on specific conditions
power source type	AC-DC dual-use	Recommended DC reverse connection (DC+)

🏭typical application scenarios

With its“ dual characteristics of high temperature resistance and corrosion resistance”, QDE D802 cobalt-based electrode is active in the following core industrial fields:
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High temperature and high pressure valve:
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It is specially used for surfacing and repairing sealing surfacesof gate valves,globe valves andcheck valves inpower stations, which is the core application field.
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Chemical and petroleum equipment:
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Used forhigh pressure pump shaft sleeve,inner liner,chemical fiber equipment cutting edge, etc. to withstand corrosion and wear parts.
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Hot working machinery:
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Suitable forhot shear blade,hot forging die,screw feeder and other work in high temperature wearing parts repair.
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Other wear parts:
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Used forroller bit bearings,boiler rotating impeller, etc. need high temperature wear resistance occasions.

💡Welding process recommendations

In order to ensure that the quality of D802 electrode to play the best performance, avoid cracks and pores, it is recommended that you follow the following process points during construction:
1.& nbsp;
Electrode drying:
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Before welding, the electrode must be baked at150℃-200 ℃ for more than1 hourto remove moisture from the coating and prevent porosity during welding.
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Workpiece cleaning:
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Before welding, theoil stain, rust, oxide scale and moistureon the surface of the workpiece must be thoroughly removed to expose the metallic luster.
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Preheating and interpass temperature:
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Depending on the size of the workpiece and the type of base metal, preheating at300-600 ° C isrecommended. The interlayer temperature should be controlled at about300-350 ° Cto prevent cracks from occurring.
4.& nbsp;
Welding specification:
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Current selection: It is recommended to uselow current andshort arc welding to reduce the penetration depth of the base metal, reduce the dilution rate, and ensure the alloy performance of the surfacing layer.
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Operation method: Use short arc operation as far as possible, and keep the electrode perpendicular to the working surface.
5.& nbsp;
Post-weld cooling:
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After welding,slow cooling treatment shall be carried out immediately. It is recommended to place the workpiece in a dry and preheated sandbox or straw ash for slow cooling, or immediately place the workpiece in asbestos felt for heat preservation and slow cooling. It is strictly prohibited to quench (such as watering) to eliminate welding stress and prevent cracks.

📝sum up

D802 Co-base welding rodis the golden key to solve the problems of high temperature and high pressure valve sealing surface wear, hot shear blade repair and corrosion resistance and wear parts strengthening. It provides you with a solid industrial guarantee with stable cobalt-based alloy quality and excellent welding process performance.
If you are looking for ahigh temperature,corrosion andimpact resistant surfacing solution, Quality D802 is your trusted industrial partner.