Custom Stainless Steel Casting: China High Quality Foundry

1. Panimula

Stainless steel casting is a critical manufacturing process used to create high-performance components across industries that demand corrosion resistance, tibay ng katawan, and dimensional precision.

By pouring molten stainless steel into custom-designed molds, complex parts can be produced with tight tolerances and excellent surface finishes, making it an ideal solution for intricate and high-strength applications.

Compared to other metal forming methods such as forging or machining, stainless steel casting offers enhanced design freedom, kahusayan sa materyal, and suitability for low-to-medium production volumes.

Its significance has grown in sectors such as energy, automotive, aerospace, pagproseso ng pagkain, and marine engineering, where performance and longevity are non-negotiable.

2. What is Stainless Steel Casting?

Hindi kinakalawang na asero casting is a precision metal forming process in which molten stainless steel is poured into a mold to create complex and high-performance components.

It combines the corrosion-resistant properties of stainless steel with the dimensional accuracy and design flexibility of modern casting techniques.

This process allows manufacturers to produce parts with intricate geometries, manipis na pader, and fine surface finishes that are difficult or uneconomical to achieve through machining or forging.

Stainless steel casting can be carried out using various methods, kasama ang paghahagis ng pamumuhunan, buhangin paghahagis, and shell mold casting, Depende sa laki ng bahagi, hugis, at mga kinakailangan sa pagganap.

It supports a wide range of stainless grades—such as austenitic, martensitic, Duplex, and precipitation-hardened steels—offering tailored mechanical properties for strength, tigas na tigas, o paglaban sa init.

3. Common Stainless Steel Grades for Casting

Stainless steel casting encompasses a wide range of alloys, each engineered to meet specific performance criteria.

These grades are categorized primarily based on their microstructure: austenitic, martensitic, ferritic, Duplex, and precipitation-hardening (PH) hindi kinakalawang na asero.

Common Stainless Steel Grades for Casting

4. Stainless Steel Casting Methods

Hindi kinakalawang na asero Investment Casting (Nawala ang Wax Casting)

Pamumuhunan sa paghahagis is a precision casting technique that begins with the creation of a wax model that replicates the final part geometry.

This wax pattern is assembled onto a wax tree (for batch processing) and repeatedly dipped into a ceramic slurry to build a shell.

After the ceramic hardens, the entire mold is heated to melt out the wax (Pag-aalis ng Wax), leaving a hollow ceramic cavity.

Molten stainless steel is then poured into the heated shell, allowing for detailed filling.

Minsan nang tumibay, the ceramic shell is broken away, and the casting is cleaned, init na ginagamot, and finished as required.

• The shell can withstand high temperatures, enabling intricate and thin-walled castings.
• Common for parts requiring tight dimensional tolerances (±0.1 mm), makinis na ibabaw ay nagtatapos (Ra 3.2–6.3 μm), and complex internal features.

Hindi kinakalawang na asero buhangin paghahagis

Sand casting utilizes a disposable mold made from silica sand, typically bonded with clay or chemical binders.

A wooden or metal pattern is pressed into the sand to form a negative cavity. For complex internal features, sand cores are inserted.

The mold halves are clamped, and molten stainless steel is poured into the cavity through a gating system.

Pagkatapos ng paglamig at solidification, the sand mold is broken away, revealing the rough casting.

• This method is highly flexible in terms of size and weight—capable of producing parts from a few kilograms to several tons.
• Tolerances are looser (±1.5 mm or more), and surface finish is coarser (Ra 12.5–25 μm), often requiring post-machining.

Stainless Steel Shell Mold Casting

Paghahagis ng amag ng shell is a variation of sand casting that uses resin-coated, fine-grain sand and a heated metal pattern.

The heated pattern causes the resin to cure as the sand contacts it, Bumubuo ng isang manipis, rigid shell (typically 5–10 mm thick).

The shell halves are then removed from the pattern, assembled, and filled with molten stainless steel.

Pagkatapos ng paglamig, the shell is broken away, and the part is finished similarly to investment or sand castings.

• Provides better dimensional accuracy (±0.5 mm) at ibabaw tapusin (Ra 6.3–12.5 μm) than traditional sand casting.
• Especially suitable for medium-to-high volume production of geometrically simpler parts.

Stainless Steel Centrifugal Casting

Sa centrifugal casting, a hollow cylindrical mold is rotated at high speeds (300–3000 RPM) while molten metal is poured into it.

The centrifugal force pushes the molten metal outward toward the mold walls, resulting in a dense, fine-grained structure with minimal porosity.

The axis of rotation can be horizontal (for pipes) or vertical (for rings or gear blanks).

As the casting solidifies from the outer surface inward, impurities are forced toward the inner diameter and can be machined away.

• This process yields excellent mechanical properties and uniform grain orientation due to directional solidification.
• Ideal for applications requiring high strength, pressure resistance, and minimal inclusions.

Stainless Steel Metal Mold (Permanent Mold) Paghahagis

Metal mold casting uses permanent steel or cast iron molds instead of disposable sand or ceramic molds.

Molten stainless steel is introduced either by gravity, mababang presyon, or vacuum assistance into the pre-heated mold.

The mold may include retractable cores or inserts for more complex geometries. Kapag ang metal ay lumamig at tumibay, ang amag ay binuksan, and the part is ejected for finishing.

• Produces consistent, repeatable results with tight tolerances (±0.25-0.5 mm) and superior surface finish (Ra 3.2–6.3 μm).
• Economical for medium-to-high production volumes due to fast cycle times and reduced labor.

5. Stainless Steel Casting Process: Hakbang sa Hakbang (Investment Casting Example)

1. Paglikha ng Pattern: Wax patterns (±0.02 mm tolerance) are injection-molded; multiple patterns are attached to a wax tree.
2. Shell Building: Patterns are dipped in ceramic slurry (silica/alumina) and coated with sand, repeating 6–8 times to build a 6–10 mm shell.
3. Dewaxing and Shell Firing: Shells are heated to 160–200°C to melt wax (recycled), then fired at 900–1,050°C to harden the ceramic.
4. Pagbubuhos ng: Molten stainless steel (1,450–1,530°C for CF8M) is poured into the shell under gravity or vacuum to avoid porosity.
5. Paglamig at Solidification: Controlled cooling (air or water) prevents hot cracking; solidification time: 5–30 minuto (varies by part size).
6. Knockout and Cleaning: Shells are shattered with hammering or water jets; gates/risers are cut, and parts are sandblasted to remove ceramic residue.
7. Paggamot ng Heat: Mga marka ng Austenitic (CF8, CF8M) are solution-annealed (1,050-1,150 ° C, water-quenched) to dissolve carbides. Martensitic grades (CA15) are quenched and tempered for hardness.
8. Inspeksyon: Dimensional checks (CMM), NDT (Tinain na penetrant), and mechanical testing (lakas ng paghatak) ensure compliance.

6. Surface Finishing Options of Stainless Steel Casting

Surface finishing of stainless steel castings is critical for both functional performance (hal., paglaban sa kaagnasan, Paglaban sa Pagsusuot) at aesthetic appeal.

The choice of finish depends on the application—from food-grade parts requiring ultra-smooth, hygienic surfaces to industrial components needing enhanced durability.

Pagsabog ng Shot

Shot blasting uses high-velocity abrasive media (Bakal na Grit, ceramic beads, o salamin) to clean and texture casting surfaces.

• Proseso: Media is propelled at 60–100 m/s via compressed air or centrifugal wheels, Pag-aalis ng mga kontaminante sa ibabaw (hal., ceramic residue from investment casting) and creating a uniform matte texture.
• Results: Pagkamagaspang sa ibabaw (Ra) of 3.2–6.3 μm; improves adhesion for paints, mga patong na patong, or powder finishes.
• Mga Aplikasyon: Industrial valve bodies, Mga pabahay ng pump, and structural castings where a textured surface aids in coating retention.

Pag-aatsara at Passivation

These chemical treatments enhance corrosion resistance by removing impurities and stabilizing the chromium oxide passive layer.

• Email Address *: Uses a nitric-hydrofluoric acid solution to dissolve scale, kalawang, and free iron from casting surfaces. Critical for removing heat tint (oksihenasyon) from welded or heat-treated areas.
• Passivation: Follows pickling, using nitric acid to enrich the chromium content in the surface oxide layer, pagpapalakas ng paglaban sa kaagnasan. Complies with ASTM A967 for stainless steels.
• Results: Clean, oxide-free surface with Ra 1.6–3.2 μm; prevents pitting in chloride environments (hal., tubig dagat).
• Mga Aplikasyon: Kagamitan sa pagpoproseso ng pagkain (304 Mga Paghahagis), mga bahagi ng dagat (316 Mga Paghahagis), and medical devices requiring biocompatibility.

Electropolishing

Electropolishing is an electrochemical process that removes a thin layer of metal (5-50 μm) to achieve a mirror-like finish.

• Proseso: The casting acts as the anode in an electrolyte bath (phosphoric/sulfuric acid), with current dissolving surface irregularities.
• Results: Ultra-smooth surface (Ra 0.025–0.1 μm) with improved cleanliness—microscopic pores and crevices (potential sites for bacterial growth) are eliminated.
• Mga kalamangan: Enhances corrosion resistance by 30–50% vs. passivation alone; reduces friction in dynamic applications (hal., sliding parts).
• Mga Aplikasyon: Pharmaceutical equipment (316L castings), kirurhiko instrumento, and semiconductor components where particle shedding must be minimized.

Machining and Surface Tolerance

For castings requiring tight dimensional control or precise mating surfaces, machining is often paired with finishing:

• Turning/paggiling: Removes 0.1–1 mm of material to achieve tolerances as tight as ±0.01 mm (hal., valve seats requiring leak-tight seals).
• Paggiling: Surface grinding achieves flatness within 0.005 mm/m and Ra 0.05–0.1 μm, critical for bearing surfaces in aerospace castings.
• Threading/Tapping: Creates precise threads (ISO metric or NPT) in cast flanges or fittings, ensuring compatibility with piping systems.

Other Finishes

• Bead pagsabog: Uses softer media (Mga kuwintas ng salamin) than shot blasting to create a uniform, satin finish (Ra 1.6–3.2 μm) without altering dimensions.
  Common in architectural castings (hal., Mga handrail) for aesthetic appeal.
• Electroplating: Applies a thin layer of nickel, Chrome, or gold for decorative purposes or enhanced wear resistance.
  Used in high-end fixtures (hal., hardware ng dagat) where appearance is critical.
• Laser Engraving: Adds permanent markings (mga numero ng bahagi, mga logo) to cast surfaces without compromising corrosion resistance, essential for traceability in aerospace and medical applications.

7. Mechanical and Physical Properties of Stainless Steel Casting

8. Advantages of Stainless Steel Casting

• Complex Geometry: Produces undercuts, manipis na pader (≥1 mm for investment casting), and internal cavities—e.g., CF8M valve bodies with multi-port designs.
• Tapos na ang Superior Surface: Investment casting achieves Ra 1.6–3.2 μm as-cast, reducing post-processing.
• Kahusayan sa Materyal: 70–90% material utilization vs. 30–50% for machining, lowering raw material costs.
• Kakayahang umangkop sa Disenyo: Enables part consolidation (hal., replacing 5 machined components with 1 cast part, reducing assembly costs by 40%).
• Alloy Versatility: Compatible with grades from low-cost 430 to high-performance 310 (25Cr-20Ni) for extreme heat.

9. Mga Limitasyon at Hamon

• Mas Mataas na Gastos: 30–50% more expensive than carbon steel casting due to alloying elements (hal., nickel in 304).
• Long Lead Times: Investment casting requires 2–4 weeks for tooling and first parts, mga bes. 1–2 weeks for sand casting.
• Defect Risks: Pag-urong (1.5–2.0% volume reduction) and hot cracking (in martensitic grades) without precise process control.
• Thick Section Challenges: Sections ≥50 mm risk porosity due to slow cooling; requires risers (extra metal reservoirs) to feed molten steel.

10. Applications of Stainless Steel Castings

Industriya ng Aerospace

• Mga Bahagi: Mga blades ng turbine, mga impeller, mga bahagi ng engine, mga bahagi ng istruktura, mga sistema ng tambutso.

Industriya ng Automotive

• Mga Bahagi: Exhaust manifolds, Mga pabahay ng turbocharger, Mga Caliper ng Preno, mga bahagi ng suspensyon.

Industriya ng Kemikal at Petrochemical

• Mga Bahagi: Mga Valve, mga bomba, Mga kagamitan sa tubo, mga bahagi ng reaktor, mga heat exchanger.

Food Processing Industry

• Mga Bahagi: Mixers, Mga balbula, mga bomba, conveyor components, processing equipment.

Marine and Shipbuilding Industry

• Mga Bahagi: Mga propeller, mga shaft, Mga balbula, Mga Casing ng Bomba, seawater piping components.

Power Generation Industry (Including Nuclear and Renewable Energy)

• Mga Bahagi: Mga bahagi ng turbina, mga katawan ng balbula, Mga Casing ng Bomba, generator parts.

Construction and Heavy Equipment

• Mga Bahagi: Mga bahagi ng haydroliko, excavator parts, structural castings, lifting equipment.

Medical and Pharmaceutical Industry

• Mga Bahagi: Mga instrumento sa kirurhiko, sterilization equipment, mga bahagi ng pump, mga katawan ng balbula.

Water Treatment and Plumbing

• Mga Bahagi: Mga Valve, Mga kagamitan sa tubo, Mga pabahay ng pump, filter components.

Mga Makinarya sa Industriya

• Mga Bahagi: Mga Gear, mga pabahay, bearing supports, mga base ng makina, haydroliko mga bahagi.

11. Stainless Steel Casting vs. Forging and Machining

12. Kontrol at Pagsubok sa Kalidad

• Pagsubok na Hindi Nakasisira (NDT):

• • X-ray: Detects internal porosity (critical for pressure vessels).
  • Ultrasonic: Identifies cracks in thick sections (hal., duplex pipe flanges).
  • Dye Penetrant: Reveals surface defects in martensitic valve stems (ASTM E165).

• Dimensional na Inspeksyon: CMM (Coordinate Pagsukat Machine) verifies tolerances to ±0.005 mm.
• Chemical Analysis: Optical emission spectrometry (OES) confirms alloy composition (hal., 18±1% Cr in CF8).
• Pagsubok sa Mekanikal: Tensile tests (ASTM A370) and impact tests (Charpy V-bingaw) validate strength and toughness.

13. Pangwakas na Salita

Stainless steel casting is a versatile process that balances complexity, paglaban sa kaagnasan, at gastos, enabling the production of critical components across industries.

Its ability to transform molten stainless steel into intricate, high-performance parts—from marine valves to medical implants—makes it irreplaceable in modern manufacturing.

While challenges like cost and lead times persist, advances in process control (hal., computer simulation of solidification) and material science (hal., high-entropy alloys) continue to expand its capabilities.

LangHe: Precision Stainless Steel Casting & Fabrication Services

LangHe is a trusted provider of high-quality stainless steel casting and precision metal fabrication services, serving industries where performance, tibay ng katawan, and corrosion resistance are critical.

With advanced production capabilities and a commitment to engineering excellence, LangHe delivers reliable, customized stainless steel solutions to meet the most demanding application requirements.

Our Stainless Steel Capabilities Include:

• Pamumuhunan sa Paghahagis & Nawala ang Wax Casting
  High-precision casting for complex geometries, ensuring tight tolerances and superior surface finishes.
• buhangin paghahagis & Paghuhulma ng Shell
  Ideal for larger components and cost-effective production, especially for industrial and structural parts.
• CNC Machining & Pagkatapos ng Pagproseso
  Complete machining services including turning, paggiling, pagbabarena, buli na, and surface treatments.

Whether you need high-precision components, complex stainless assemblies, or custom-engineered parts, LangHe is your dependable partner in stainless steel manufacturing.

Makipag ugnay sa amin ngayon to learn how LangHe can deliver stainless steel solutions with the performance, pagiging maaasahan, and precision your industry demands.

Mga FAQ

What is the best method for stainless steel casting?

Depends on part requirements: Investment casting for precision (±0.05 mm) at pagiging kumplikado; sand casting for large, low-cost parts; centrifugal casting for cylindrical components like pipes.

How strong is cast stainless steel?

Mga marka ng Austenitic (CF8, CF8M) have tensile strengths of 550–650 MPa; martensitic CA15 (410) reaches 800 MPa when heat-treated; duplex CD4MCu exceeds 690 MPa.

Can cast stainless steel be welded?

Oo nga. Mga marka ng Austenitic (CF8, CF8M) weld well with 308L filler; martensitic grades require preheating (200–300°C) and post-weld annealing to avoid cracking.

What is CF8M stainless steel casting used for?

CF8M (cast 316) is ideal for corrosive environments: chemical processing valves, offshore oil fittings, at marine hardware, thanks to its molybdenum-enhanced chloride resistance.