Casting Steels

Alternative Material Options

If the performance demands extend beyond the capabilities of standard casting steels, several high-performance alternatives are available. For high-temperature service or oxidation-resistant environments, Inconel alloys and nickel-based casting superalloys deliver superior creep and corrosion resistance. When extreme wear or metal-to-metal contact is involved, Stellite cobalt-based alloys offer unmatched hot hardness and galling resistance. For lightweight structures that require both strength and reduced density, engineered titanium alloys offer excellent fatigue and corrosion resistance. In environments with aggressive chemicals or high corrosion demands, Hastelloy alloys or Monel alloys may be preferred. When directional mechanical properties are needed, equiaxed crystal casting or directional solidification superalloys can be selected to improve fatigue and creep resistance.

International Equivalent / Comparable Grade

Design Purpose

Casting steels used in investment casting are developed to deliver high structural strength, excellent toughness, and reliable fatigue performance while maintaining superior castability for complex geometries. Their metallurgical design allows for controlled solidification, minimized shrinkage, and uniform microstructures that respond well to post-casting heat treatment. The material system is designed to support near-net-shape components, such as housings, brackets, pump bodies, impellers, gears, and load-bearing structures, without the excessive machining typically required for wrought steels. By combining the high-precision capabilities of vacuum investment casting with alloy-specific heat treatments, casting steels provide consistent dimensional accuracy, smooth surfaces, and mechanical robustness for industrial, aerospace, and energy applications.

Chemical Composition

Physical Properties

Mechanical Properties

Key Material Characteristics

• High structural strength suitable for load-bearing and impact-resistant components.

• Excellent toughness and ductility, reducing failure risk under cyclic or shock loading.

• Reliable castability in investment casting with stable fluidity and minimal shrinkage defects.

• Good dimensional consistency and surface quality, reducing machining requirements.

• Wide heat-treatability enabling tailored hardness, toughness, and tensile properties.

• Cost-effective alternative to high-nickel or cobalt superalloys for moderate temperature applications.

• Compatible with precision machining for tight-tolerance features and sealing surfaces.

• Suitable corrosion and oxidation resistance when alloyed with chromium and nickel.

• Good fatigue resistance for rotating and cyclically loaded components in industrial machinery.

• Broad availability and well-established metallurgy simplify material certification and replacement.

Manufacturability And Post Process

• Investment casting: Produces thin-wall, complex geometries with excellent surface finish and tight tolerances.

• Special alloy casting: Supports custom alloy chemistry and project-specific casting steels.

• Heat treatment: Critical for achieving target hardness, strength, and microstructural refinement.

• Hot Isostatic Pressing (HIP): Enhances fatigue life and structural integrity by eliminating micro-porosity.

• CNC machining: Delivers high precision on sealing faces, bores, threaded holes, and mating surfaces.

• EDM processing: Used for difficult internal features or hardened sections.

• Deep hole drilling: Enables long, accurate channels in structural or hydraulic components.

• Welding and repair processes such as TIG/MIG and hardfacing support tool refurbishment and lifecycle extension.

• Post-finishing including grinding, polishing, and shot peening improves fatigue resistance and surface integrity.

• Material testing and analysis ensures quality through tensile, impact, metallography, and NDT validation.

Suitable Surface Treatment

• Carburizing or nitriding for improved surface hardness and wear resistance.

• Heat treatment for strength/hardness tuning, including quench and temper cycles.

• Shot peening to improve fatigue strength in dynamic components.

• Phosphate coatings to enhance corrosion resistance and break-in wear behavior.

• Thermal spray coatings for high-temperature oxidation and erosion protection.

• Precision grinding and polishing for sealing surfaces and low-roughness requirements.

• Passivation to improve corrosion behavior in energy and process environments.

• Inspection and validation coatings verified by testing and analysis.

Common Industries and Applications

• Power generation: Turbine brackets, impellers, structural fittings, support frames.

• Oil and gas: Valve bodies, pump housings, wellhead components requiring strength and reliability.

• Chemical processing: Reactors, mixers, and components in moderate-corrosion conditions.

• Aerospace: Structural brackets, mounting hardware, load-bearing housings.

• Defense: Ruggedized components, vehicle structures, and weapon system hardware.

• Marine: Structural supports, chain fittings, machinery housings.

• Mining: Wear-resistant, impact-loaded cast steel components.

• General machinery: Gear housings, levers, clamps, and heavy-duty mechanical elements.

When to Choose This Material

• Moderate-to-high structural loads: Excellent choice for components subjected to continuous mechanical stress.

• Impact or shock loading: Preferred for parts requiring high toughness and reliable energy absorption.

• Complex geometries: Ideal when investment casting enables near-net shapes and reduced machining.

• Cost-sensitive applications: Provides strong mechanical performance at a lower cost than superalloys or titanium.

• Machining flexibility: Suitable when post-machining is required for tight tolerances and precise sealing surfaces.

• Fatigue or cyclic loading: Good performance for rotating machinery, pumps, and industrial equipment.

• High reliability and lifecycle value: Recommended where predictable material behavior and long service life are important.

• Medium-temperature environments: Effective for service conditions up to ~500°C, depending on alloy design.