Understanding Alloy Steel Composition: 36% Nickel Alloy

Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1 and 50% by weight to improve its mechanical properties. Different alloying elements give steel different characteristics.

The question specifically asks about an alloy steel containing approximately 36% nickel.

Let's look at the options provided:

• Invar: Invar is a nickel-iron alloy, typically consisting of about 36% nickel and the balance iron. It is famous for its very low coefficient of thermal expansion, which means its size changes very little with temperature changes. This unique property makes Invar alloy steel useful in applications requiring high dimensional stability, such as precision instruments, clocks, seismic creep gauges, and scientific apparatus.
• Stainless steel: Stainless steel is primarily an alloy of iron, chromium (usually at least 10.5% by mass), and often nickel, carbon, and other elements. The main characteristic of stainless steel is its resistance to corrosion, which is provided by the chromium content. While some types of stainless steel contain nickel, their primary distinguishing feature is chromium, not a high percentage of nickel around 36%.
• High speed steel: High speed steel (HSS) is a type of tool steel commonly used for cutting tools. It is known for its hardness, resistance to abrasion, and ability to retain its hardness at high temperatures (red hardness). HSS typically contains alloying elements like tungsten, molybdenum, chromium, and vanadium. Nickel is not a primary alloying element in standard high speed steels in such a high percentage.

Based on the typical composition of these materials, the alloy steel containing approximately 36% nickel is known as Invar.