Stellite 21 alloy has excellent resistance to wear, corrosion and high temperatures. The following are the general characteristics of Stellite 21 cobalt-based alloys:
Abrasion resistance: Stellite 21 alloy has excellent wear resistance and is able to withstand friction, wear and abrasive particles. It is commonly used in the manufacture of wear-resistant parts such as valves, bearings, knives, etc.
Corrosion resistance: The alloy exhibits good corrosion resistance and is able to resist the erosion of corrosive media such as acids, alkalis, and salt water. This makes Stellite 21 alloy widely used in chemical, oil and gas applications.
High temperature stability: Stellite 21 alloy is able to maintain its strength and stability in high temperature environments, and has good high temperature properties. It is suitable for applications that require high temperature and wear resistance, such as aerospace, energy, and high-temperature processes.
Weldability: Stellite 21 alloy has good weldability and can be joined with other metal materials, increasing the flexibility and versatility of its application.
Cobalt-based alloy electrode surfacing analysis.
Low equipment**, good adaptability makes electrode arc welding applications very common. Carbon steels, low-alloy steels, high-alloy steels, and many non-ferrous metals, as well as base metal thicknesses from 6 mm to 450 mm or thicker, can be arc welded with electrodes. Electrode arc welding, overlay carbon steel valve body requires a low dilution rate and suitable hardness to ensure overlay performance. Welding processes such as welding current, polarity, welding operation, weld bead spacing, etc., have a great impact on the dilution rate.
The influence of process parameters on the dilution rate of the surfacing layer is as follows: the dilution rate increases when the overlay current increasesThe pitch of the surfacing weld bead increases, and the dilution rate increases, (the pitch refers to the superposition distance of two adjacent weld beads);The reduced welding speed increases the melting of the base metal and increases the amount of filler metal added, thereby reducing the dilution rate [3].
3. Surfacing process test and surfacing process formulation.
3.1. Surfacing process test.
Assessment basis: ASME-2010 "Welding and Brazing Evaluation". Specimen material: A216 WCB.
Welding material: Stellite21 electrode, O40 mm, bake 250, l h
Specimen dimensions: 200 mm x 200 mm x 30 mm.
Chemical Composition: