The classic “18-4-1” high-speed steel designation indicates approximate mass percentages of which alloying elements, in order?

Introduction / Context:High-speed steels (HSS) retain hardness at elevated cutting temperatures. The numeric shorthand (e.g., 18-4-1) encodes the principal alloying elements that deliver hot hardness, wear resistance, and secondary hardening.

Given Data / Assumptions:

• Designation: 18-4-1 (T1-type HSS).
• Interpretation: percentages correspond to W, Cr, and V respectively.

Concept / Approach:In 18-4-1 HSS, the three numbers refer to ~18% tungsten, ~4% chromium, and ~1% vanadium. Tungsten provides hot hardness via carbides; chromium contributes hardenability and corrosion resistance; vanadium improves wear resistance and grain refinement.

Step-by-Step Solution:1) Map 18 → W; 4 → Cr; 1 → V.2) Evaluate options to find the sequence W–Cr–V.3) Select “tungsten, chromium and vanadium.”

Verification / Alternative check:Standard references for T1 HSS confirm the W–Cr–V interpretation for 18-4-1, with minor additions of carbon and others as specified.

Why Other Options Are Wrong:Reordered sequences misrepresent the standard convention; substituting molybdenum or changing positions does not fit the canonical designation.

Common Pitfalls:Confusing Mo-based HSS (like M2) with W-based HSS (T1). Always verify the numeric shorthand mapping.

Final Answer:tungsten, chromium and vanadium