Luoyang Golden Egret Hard Facing Materials Product--Introduction of Thermal Spray Powder Applied To Ball Valves in Petrochemical Industry.

Thermal spray is a new technology of surface strengthening and protecting, is a great part of surface modification. As the development of science and technology, thermal spray technology has obtained extensive promotion and application all over the country, especially towards ball valves among petrochemical industry. For the situation where high temperature, high pressure and medium containing solid particles exist at the same time, hard sealed ball valve is a kind of commonly approved valve.

Luoyang Golden Egret Hard Facing materials division has WC-10Co-4Cr.Cr3C2-25(NiCr) .WC-20Cr3C2-9Ni, mainly used for hard seal materials of ball valves. The powder is even in composition, with concentrated particle size distribution, stable apparent density, highly spherical shape. Applying with HVOF craft to form a WC based of Cr3C2 based coating structure on the surface of ball valves. The sealed face formed after process has a great abrasion and corrosion resistance, high temperature resistance and sealability, so as to extend the service life of ball valves. Inside water, gas and oil medium, the service life will be increased to 10-20 times, under the environment of severe wash-out, the service life could be increased to more than 5 times.

For the three compositions of powder, we provide different grade, but the process is all the same: agglomerated and sintered.

01. Product Series

WC-10Co-4Cr: GP10C-2 (15-38um, apparent density 4.4-5.2g/cm3)

GP10C-7(10-38um, apparent density≥4.2 g/cm3)

Cr3C2-25(NiCr): GP25NC(15-45um, apparent density≥2.3 g/cm3)

GP25NC-7(10-38um, apparent density≥2.3 g/cm3)

WC-20Cr3C2-9Ni: GP09N (15-45um, apparent density 3.7-4.7g/cm3)

GP09N-19 (5-30um, apparent density 3.7-4.7g/cm3)

02. Coating Performance

The coating performance is excellent applied with HVOF, details as follows:

1) Metallographic Structure

Dense coating, great bonding with matrix, oxide is unseen, WC.Cr3C2 particles are distributed evenly.

2) Porosity

Porosity is less than 0.5%

3) Bonding Strength

Bonding strength is greater than 70MPa

4) Micro Hardness

Micro harness test press of coating is good, no subside, the hardness is consistent
WC-10Co-4Cr HV_0.3 1100-1350

Cr₃C₂-25(NiCr) HV_0.3 850-1100

WC-20Cr₃C₂-9Ni HV_0.3 1000-1200

5) Coating Corrosion Resistance

Under standardized salt spray test, no obvious corrosion trace appeared after 240H.

6) Coating Sealing Property

The coating has great sealing property, passes the dye penetrant inspection.

7) Coating High Temperature Resistance

The coating has excellent high temperature resistance, the applying temperature of WC-10Co-4Cr series is ≤540℃, the applying temperature of Cr3C2-25(NiCr) series is ≤870℃ and for WC-20Cr3C2-9Ni series, the applying temperature is ≤760℃.

Introduction of Thermal Spray Powder Coating Application on Hard Seal Ball Valves in Petrochemical Industry.

WC-10Co-4Cr series: Medium WC used, with great wear resistance and corrosion resistance, mainly applied to hard seal working condition required of high hardness, high corrosion resistance.

Cr3C2-25(NiCr) series: Using Cr3C2 for hard phase, great abrasion resistance, excellent corrosion and high temperature resistance, mainly applied to hard seal working condition required of high corrosion and high temperature resistance.

WC-20Cr3C2-9Ni series: Medium WC used, Cr3C2 for hard phase, great wear resistance, excellent corrosion and high temperature resistance, mainly applied to hard seal working condition required of high abrasion resistance, high corrosion resistance.