The difference between steel and stainless steel is mainly reflected in the composition, performance and application scenarios, the following is a summary of the core differences:

1. Composition differences

    ● Steel (ordinary steel)

        The main composition is iron (Fe) and carbon (C), the carbon content is 0.02%~2.11%, which belongs to carbon steel or alloy steel (if a small amount of other elements such as manganese, silicon, etc.).

        Ordinary steel does not contain or only contains a small amount of chromium (Cr), nickel (Ni) and other alloying elements.

    ●  Stainless steel

        At least 10.5% chromium (Cr) is added on the basis of steel, and some types also contain nickel (Ni), molybdenum (Mo), titanium (Ti) and other elements.

    ● Typical categories:

        304 stainless steel: containing 18% chromium, 8% nickel, excellent corrosion resistance.

        316 stainless steel: added 2% molybdenum, seawater and high temperature corrosion resistance.

2. performance comparison

    ●  Corrosion resistance

        Stainless steel: Chromium element reacts with oxygen to form a dense oxide film (passivation film), which significantly resists the corrosion of air, water, acid and alkali and other media.

        Ordinary steel: easy to oxidize and rust, especially in wet or salty environments.

    ●  Physical property

        Strength and toughness: ordinary steel can achieve high strength and toughness through heat treatment, suitable for load-bearing structures; Stainless steel has higher hardness but lower ductility.

        Surface characteristics: stainless steel is silver-white luster, ordinary steel color is dark, the surface is easy to scratch.

     ●  Other characteristics

        Density: Ordinary steel is about 7.85 tons /m³, stainless steel is slightly different due to different components (such as 430 stainless steel is 7.75 tons /m³).

        Magnetic: ordinary steel is magnetic; Some stainless steels (such as austenitic 304) are non-magnetic, while martensitic stainless steels (such as 430) are magnetic.

3. Application fields

    ●  Plain steel

        Construction: steel structure frame, rebar, etc.

        Machinery manufacturing: auto parts, tools, cutting tools, etc.

    ●  Stainless steel

        Corrosion resistance scenario: food processing equipment (304), medical equipment (316L), chemical pipeline, Marine engineering (316).

         Decoration and precision field: building curtain wall, high-end home appliances, microelectronics equipment.

4, cost and processing

    Cost: Because stainless steel contains high-priced alloying elements (such as nickel and molybdenum), the cost is significantly higher than that of ordinary steel.

     Processing difficulty: Stainless steel requires a special welding process (such as argon arc welding protection), ordinary steel processing is easier.