Cast Steel vs. Forged Steel Valves: Selection and Distinctions
What are Cast Steel Valves?
Cast steel valves are crafted using three types of casting alloys: cast carbon steel, cast low-alloy steel, and cast special steel. Cast carbon steel is employed for manufacturing parts with complex shapes that are challenging for forging or machining and demand high strength and plasticity. Cast steel valves offer good economic efficiency and are suitable for cost-sensitive applications.
What are Forged steel Valves？
Forged steel valves are produced through forging methods, ensuring higher quality, greater resistance to impact forces, and superior mechanical properties such as plasticity and toughness. Despite being relatively more expensive, forged steel valves are the preferred choice in industries where heightened performance and reliability are paramount. However, these valves typically have a smaller nominal diameter, usually below DN50.
Introduction to Forged Technique
Closed Die Forging (Die Forging, Rotary Forging, Cold Heading, Extrusion): Involves subjecting metal blanks to pressure within a forging die of a specific shape.
Open Die Forging (Hand Forging and Mechanical Forging): Involves placing metal blanks between two anvils (dies) and using impact force or pressure to achieve the desired forging.
Forging Materials: Primarily composed of various carbon steels and alloy steels, followed by aluminum, magnesium, titanium, copper, and their alloys. The initial states of materials include bars, ingots, metal powders, and liquid metals.
Detailed Overview of Cast Technique
Types of Casting: Includes ordinary sand casting (dry sand, wet sand, and chemical hardening sand) and special casting.
1. Preparation of Casting Molds: Classifiable as one-time, semi-permanent, and permanent molds, and based on materials as metal, sand, clay, ceramic, graphite, etc.
2. Melting and Pouring of Casting Metal: Involves casting metals such as cast iron, cast steel, and non-ferrous alloys.
3. Treatment and Inspection of Castings: Includes the removal of core and surface impurities, cutting off sprue and riser, grinding burrs, and treatments like
4. heat treatment, shaping, rust prevention, and rough machining.
Advantages of Casting: Suited for components with complex shapes and intricate internal structures, offering cost-effectiveness.
Key Factors in Valve Selection
When choosing between cast steel and forged steel valves, specific operational requirements and budgets must be taken into account. Cast steel valves excel in economic efficiency, making them suitable for cost-sensitive scenarios. Forged steel valves, on the other hand, provide a higher level of performance and reliability, making them suitable for critical operations with elevated demands in these aspects.
In the realm of valve manufacturing, the choice between cast steel and forged steel valves involves considerations of economic efficiency, performance, and reliability. A comprehensive understanding of the characteristics of these two valve types, coupled with specific operational needs and budget constraints, is crucial for making informed decisions. As industrial technology continues to advance, making wise choices between these two materials will contribute to steering industrial operations toward greater sustainability.