E-mail: dongrun@dongruncasting.com

What is the difference between cast steel and cast iron

2022-02-11 16:43:55

What is the difference between cast steel and cast iron

1、 Different nature

1). Cast steel: refers to steel specially used for manufacturing steel castings.

2). Cast iron: general term for an alloy consisting mainly of iron, carbon, and silicon.


2、 Different characteristics

1). Cast steel: greater design flexibility; The strongest flexibility and variability of metallurgical manufacturing; Improve the overall structural strength; Wide range of weight changes; The vibration absorption, wear resistance and mobility of steel castings are not as good as those of iron castings.


2). Cast iron: high carbon content, not malleable.


3、 Different uses

1). Cast steel: cast steel can be divided into cast alloy steel and cast carbon steel according to its chemical composition, and can also be divided into cast tool steel, cast special steel, cast and cast alloy steel for engineering and structure according to its service characteristics.


2). Cast iron: due to long annealing cycle, complex process and high cost, it is only suitable for mass production of thin-walled parts.



This paper introduces the difference between cast steel valve and cast iron in detail; Some valve knowledge materials are extracted from American Weidun VTON valve literature. After original editing, if you think the answer is helpful to you, please raise your hand and praise American Weidun VTON valve.


Among the valve body materials, cast iron and cast steel are two commonly used valve body materials. Since they are commonly used, we need to analyze their differences for selection.

cast iron.png

The main difference between cast iron and iron steel valves is the carbon content, which directly affects the strength and plasticity of steel. Carbon steel is also called carbon steel. It is an iron carbon alloy with carbon content WC less than 2%. In addition to carbon, carbon steel generally contains a small amount of silicon, manganese, sulfur and phosphorus. According to the purpose, carbon steel can be divided into carbon structural steel, carbon tool steel and free cutting structural steel. Carbon structural steel is also divided into building structural steel and machine manufacturing structural steel. According to the carbon content, carbon steel can be divided into low carbon steel (WC ≤ 0.25%), medium carbon steel (wc0.25% - 0.6%) and high carbon steel (WC 0.6%). According to the phosphorus and sulfur content, carbon steel can be divided into ordinary carbon steel (high phosphorus and sulfur content) High quality carbon steel (low phosphorus and sulfur) and high-grade high-quality steel (low phosphorus and sulfur) generally have higher carbon content in carbon steel, the higher the hardness, the higher the strength, but the lower the plasticity.


Cast iron: cast iron is an iron carbon alloy with a carbon content of more than 2%


Cast iron can be divided into: 1. Gray cast iron 2. White cast iron 3. Malleable cast iron 4. Nodular cast iron, mainly including imported butterfly valve of nodular cast iron, imported gate valve of nodular cast iron and imported check valve of nodular cast iron; 5. Vermicular graphite cast iron 6. Alloy cast iron


Generally, the cast iron valve we call uses nodular cast iron. The gray cast iron is obtained after spheroidizing the molten iron. The precipitated graphite is spherical, which is referred to as nodular iron for short. It has higher strength, better toughness and plasticity than ordinary gray cast iron;


cast steel

Steel used for casting. A cast alloy. Cast steel is divided into cast carbon steel, cast low alloy steel and cast special steel; Cast carbon steel. Cast steel with carbon as the main alloying element and containing a small amount of other elements. Cast low carbon steel with carbon content less than 0.2%, cast medium carbon steel with carbon content of 0.2% ~ 0.5%, and cast high carbon steel with carbon content greater than 0.5%. With the increase of carbon content, the strength and hardness of cast carbon steel increase. Cast carbon steel has high strength, plasticity and toughness and low cost. It is used in heavy machinery to manufacture parts bearing heavy load, such as rolling mill frame, hydraulic press base, etc; It is used to manufacture parts with large stress and impact on railway vehicles, such as bolster, side frame, wheel and coupler;


From the above material characteristics, cast iron has stronger rigidity and brittleness than cast steel, and cast steel has better plasticity and toughness than cast iron. Therefore, cast iron is generally used in pipelines with low pressure, usually in atmospheric and normal temperature water or atmospheric and normal temperature gas; At the same time, it can only be applied to pipelines at normal temperature, because the increase of pressure or temperature indicates that the valve will have a certain amount of deformation, which is unfavorable to cast iron valves. Compared with cast iron valves, cast steel valves can be applied to pipelines with high pressure or temperature. For example, cast steel valves, high temperature and high pressure cast steel inlet stop valves, inlet gate valves, inlet check valves, etc.


Application of cast iron valve: for example, we often see the valve used to transport tap water pipeline, and the valve surface is sprayed with black paint. This kind of valve is cast iron valve.



ZheJiang Dongrun Casting Industry Co,.Ltd was built in 1995, We have been in the casting industry for more than 25 years. No matter what type of molding you need done, we are the right supplier for your jobs. Unlike other of our competition, we offer four types of castings.

sand casting

        ❖Sand casting

        ❖Gravity Die Casting

        ❖High pressure Die casting

        ❖Low pressure casting


Dongrun Casting have 20000 square meters facility houses and 200 production & test equipment, From quotation and tooling design to casting and finished machining, we  can work with you at every stage. We serves wide range of industries-from Fortune 500 corporations to small and midsize OEMs. Our products includes:

      ❖   Automotive&Trucking

      ❖   Utilities Industry

      ❖   Metering System

      ❖   HVAC

        ❖   Medical Device

        ❖   Electrical Lighting

        ❖   Architectural parts

        ❖   Furniture parts

Browse our online showroom to see what we can do for you. And then E-mail:dongrun@dongruncasting.com us your specifications or inquiries today

Related Products