Question

Which among the following is a nonferrous alloy?

• A. Brass
• B. Nickel steel
• C. Stainless steel
• D. Chromium steel

Hint:

A foolproof shortcut for alloy questions: Any option containing the word "steel" is automatically a ferrous alloy because steel is, by definition, an interstitial alloy of iron. This instantly eliminates options (B), (C), and (D), leaving Brass as the only logical answer.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The goal is to evaluate the provided list of metallurgical alloys and isolate the single non-ferrous alloy (an alloy that does not contain iron as its primary or major constituent component).

Step 2: Key Formula or Approach:
Alloys are broadly categorized into two primary divisions based on chemical composition: 1.

Ferrous Alloys: Alloys that contain iron (Fe) as the base principal metal element (e.g., all types of steel).
2.

Non-Ferrous Alloys: Alloys that do not contain iron as their primary major base component. They are composed of other metals such as copper, zinc, aluminum, or tin.

Step 3: Detailed Explanation:
Let us systematically check the composition of each option: 3.

Brass: It is an alloy composed primarily of copper (Cu, $\approx 60-70\%$) and zinc (Zn, $\approx 30-40\%$). It contains no iron in its primary formula matrix, classifying it strictly as a non-ferrous alloy.
4.

Nickel steel: A ferrous alloy containing iron combined with a specific percentage of nickel.
5.

Stainless steel: A highly common ferrous alloy consisting predominantly of iron mixed with carbon, chromium ($\ge 10.5\%$), and nickel.
6.

Chromium steel: An iron-based alloy containing chromium added to increase hardness and wear resistance.
Since options (B), (C), and (D) are all specialized classifications of steel, they are inherently ferrous alloys. Brass is the only non-ferrous choice.

Step 4: Final Answer:
The non-ferrous alloy is brass, which corresponds to option (A).