Sulfur element predominantly exerts harmful effects on tungsten-nickel-iron alloy performance: its impact is minimal at low levels, but excessive sulfur content leads to the formation of low-melting-point sulfides and grain boundary weakening, resulting in a sharp decline in impact toughness, deterioration of strength and plasticity, reduced corrosion resistance, and hindered processability.

The influence of carbon element on the corrosion resistance of tungsten-nickel-iron alloy is primarily mediated through its forms of existence (carbides, solid solution, or interfacial segregation) and its regulation of microstructure. This manifests as effects on electrochemical corrosion behavior, passivation film integrity, and corrosion morphology, with the impact varying depending on carbon content, corrosive environment, and alloy microstructure.

Sulfur element, as a typical impurity element in tungsten-nickel-iron alloy (typically introduced via raw materials or mixed in during smelting), exists in low concentrations but significantly affects the alloy’s mechanical properties, corrosion resistance, and processability. This influence is primarily realized through sulfur’s forms of existence (sulfide precipitation, grain boundary segregation) and its interaction with the matrix, exhibiting systematic variations based on sulfur content, precipitate type, and service environment.

Although carbon is typically present in trace amounts in tungsten-nickel-iron alloy, its influence on alloy performance is significant. Carbon exhibits a "double-edged sword" effect: small amounts enhance strength and hardness through solid-solution strengthening and carbide dispersion strengthening, while excessive carbon reduces toughness and fatigue resistance due to brittle phase precipitation and interface weakening.