Material: Cast Steel Process: Lost Wax Casting + CNC Precision Machining Weight: 1.80 kg Application: Pump Housing Testing: Pressure Test, Dimension Test Heat Treatment: Solid Solution
Investment castings are widely used in pumps and valves, automobile, trucks, hydraulics, forklift trucks and many other industries. Because of their exceptional casting tolerance and exellent finish, the lost wax castings are used more and more.
Stainless steel is often divided into martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to the state of microstructure. In addition, according to the chemical compositions, it can be divided into chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel, etc.
In casting production, most of the stainless steel castings are completed by investment casting. The surface of stainless steel castings produced by investment casting is smoother and the dimensional accuracy is easier to control. Of course, the cost of investment casting stainless steel parts is relatively high compared to other processes and materials.
Stainless steel has a minimum chromium content of 10.5%, making it more resistant to corrosive liquid environments and to oxidation. It is highly corrosion resistant and wear resistant, provides excellent machinability, and is well-known for its aesthetic appearance. Stainless steel investment castings are "corrosion-resistant" when used in liquid environments and vapors below 1200°F (650°C) and "heat-resistant" when used above this temperature.
Investment Casting Technical Data at RMC Foundry |
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R & D | Software: Solidworks, CAD, Procast, Pro-e |
Lead Time for Development and Samples: 25 to 35 days | |
Molten Metal | Ferritic Stainless Steel, Martensitic Stainless Steel, Austenitic stainless steel, Precipitation Hardening Stainless Steel, Duplex Stainless Steel |
Carbon Steel, Alloy Steel, Tool Steel, Heat Resistant Steel, | |
Nickle-base Alloy, Aluminium Alloy, Copper-base Alloy, Cobalt-base Alloy | |
Metal Standard | ISO, GB, ASTM, SAE, GOST EN, DIN, JIS, BS |
Material for Shell Building | Silica Sol (Precipitated Silica ) |
Water Glass (Sodium Silicate) | |
Mixtures of Silica Sol and Water Glass | |
Technical Parameter | Piece Weight: 2 gram to 200 kilo gram |
Max Dimension: 1,000 mm for Diameter or Length | |
Min Wall Thickness: 1.5mm | |
Casting Roughness: Ra 3.2-6.4, Machining Roughness: Ra 1.6 | |
Tolerance of Casting: ISO8062; VDG P690, D1/CT5-7 | |
Tolerance of Machining: ISO 2768-mk/IT6 | |
Inner Core: Ceramic Core, Urea Core, Water Soluble Wax Core | |
Heat Treatment | Normalizing, Tempering, Quenching, Annealing, Solid Solution, Carburization. |
Surface Treatment | Polishing, Sand / Shot Blasting, Zinc Plating, Nickel Plating, Oxidation Treatment, Phosphating, Powder Painting, Geormet, Anodizing |
Dimension Testing | CMM, Vernier Caliper, Inside Caliper. Depth Gauge, Height Gauge, Go/No go Gauge, Special Fixtures |
Chemical Inspection | Chemical Compostion Analysis (20 chemical elements), Cleanliness Inspection, X-ray Radiographic Inspection, Carbon-Sulfur Analyser. 3.1 Material Certificate is Available |
Physical Inspection | Dynamic Balancing, Static Blancing, Mechanical Properties (Hardness, Yield Strength, Tensile Strength), Elongation |
Production Capacity | More than 250 tons per month, more than 3,000 tons annually. |
▶ Raw Materials Available for Investment Casting (Lost Wax Casting Process)
• Carbon Steel: AISI 1020 - AISI 1060,
• Steel Alloys: ZG20SiMn, ZG30SiMn, ZG30CrMo, ZG35CrMo, ZG35SiMn, ZG35CrMnSi, ZG40Mn, ZG40Cr, ZG42Cr, ZG42CrMo...etc on request.
• Stainless Steel: AISI 304, AISI 304L, AISI 316, AISI 316L and other stainless steel grade.
• Brass & Copper.
• Other Materials and Standards on request
▶ Capabilities of Investment Casting
• Max Size: 1,000 mm × 800 mm × 500 mm
• Weight Range: 0.5 kg - 100 kg
• Annual Capacity: 2,000 tons
• Tolerances: On Request.
▶ Main Production Procedure
• Patterns & Tooling Design → Metal Die Making → Wax Injection → Slurry Assembly → Shell Building → De-Waxing → Chemical Composition Analysis → Melting & Pouring → Cleaning, Grinding & Shot Blasting → Post Processing or Packing for Shipment
▶ Inspecting Lost Wax Castings
• Spectrographic and manual quantitative analysis
• Metallographic analysis
• Brinell, Rockwell and Vickers hardness inspection
• Mechanical property analysis
• Low and normal temperature impact testing
• Cleanliness inspection
• UT, MT and RT inspection
▶ Post-Casting Process
• Deburring & Cleaning
• Shot Blasting / Sand Peening
• Heat Treatment: Normalization, Quench, Tempering, Carburization, Nitriding
• Surface Treatment: Passivation, Andonizing, Electroplating, Hot Zinc Plating, Zinc Plating, Nickel Plating, Polishing, Electro-Polishing, Painting, GeoMet, Zintec.
• Machining: Turning, Milling, Lathing, Drilling, Honing, Grinding.
▶ Why You Choose RMC for Custom Lost Wax Casting Parts?
• Full solution from one single supplier ranging customized pattern design to finished castings and secondary process including machining, heat treatment and surface treatment.
• Costdown proposals from our professional engineers based on your unique requirement.
• Short leadtime for prototype, trial casting and any possible technical improvement.
• Bonded Materials: Silica Col, Water Glass and their mixtures.
• Manufacturing flexibility for small orders to mass orders.
• Strong outsourcing manufacturing capabilities.
▶ General Commerial Terms
• Main workflow: Inquiry & Quotation → Confirming Details / Cost Reduction Proposals → Tooling Development → Trial Casting → Samples Approval → Trial Order → Mass Production → Continuous Order Proceeding
• Leadtime: Estimatedly 15-25 days for tooling development and estimatedly 20 days for mass production.
• Payment Terms: To be negotiated.
• Payment methods: T/T, L/C, West Union, Paypal.
General Casting Tolerance by Investment Casting |
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Inches | Millimeters | ||
Dimension | Tolerance | Dimension | Tolerance |
Up to 0.500 | ±.004" | Up to 12.0 | ± 0.10mm |
0.500 to 1.000” | ±.006" | 12.0 to 25.0 | ± 0.15mm |
1.000 to 1.500” | ±.008" | 25.0 to 37.0 | ± 0.20mm |
1.500 to 2.000” | ±.010" | 37.0 to 50.0 | ± 0.25mm |
2.000 to 2.500” | ±.012" | 50.0 to 62.0 | ± 0.30mm |
2.500 to 3.500” | ±.014" | 62.0 to 87.0 | ± 0.35mm |
3.500 to 5.000” | ±.017" | 87.0 to 125.0 | ± 0.40mm |
5.000 to 7.500” | ±.020" | 125.0 to190.0 | ± 0.50mm |
7.500 to 10.000” | ±.022" | 190.0 to 250.0 | ± 0.57mm |
10.000 to 12.500” | ±.025" | 250.0 to 312.0 | ± 0.60mm |
12.500 to 15.000 | ±.028" | 312.0 to 375.0 | ± 0.70mm |
Excutive Standard of Casting Tolerance: ISO 8062 2013, ISO 2768, GOST 26645 (Russia) or GBT 6414 (China). Dimensional Casting Tolerances Grade (DCTG): 4 ~6 and Geometrical Casting Tolerances Grade (GCTG): 3 ~ 5. |
During the investment casting process, a wax pattern is coated with a ceramic material, which, when hardened, adopts the internal geometry of the desired casting. In most cases, multiple parts are cast together for high efficiency by attaching individual wax patterns to a central wax stick called a sprue. The wax is melted out of the pattern – which is why it is also known as the lost wax process – and molten metal is poured into the cavity. When the metal solidifies, the ceramic mold is shaken off, leaving the near net shape of the desired casting, followed by finishing, testing and packaging.