Steel Alloy Casting Foundry Group | Pump Impeller, Diffuser, Casing and Rotating Equipment Parts

Casting Pattern Making Process

Before pattern making begins, we review all data provided by the client, including 3D models in STEP, SolidWorks, CATIA, or other 3D formats, 2D drawings, and specifications. Using this data, we create the 3D casting design. The design is then machined using programmed CAD/CAM technology to produce the pattern.

Ceramic Slurry Molding Process

First, a full set of patterns is prepared, and ceramic slurry is poured directly into the pattern. Once the slurry hardens, the vanes are drawn out from the mold. We produce a single body core to achieve maximum concentricity and dimensional accuracy. Finally, the mold is sintered inside an electric furnace to prepare it for casting.

Ceramic Slurry Mold Assembly & Pre-Heating

Similar to conventional sand casting, the drag and single body core are positioned and secured, matching the structural assembly approach of the sand casting process. The fully assembled ceramic mold undergoes a pre-heating cycle immediately prior to metal pouring.

Alphaset No-Bake Resin Molding Process

Alphaset is a no-bake resin process used to create molds by covering a pattern with sand mixed with ceramic binders to produce casting molds without thermal curing.  This mold is recommended to steel cast more complicated shapes, tighten the steel casting’s dimensional tolerances, and allow our clients to reuse the casting pattern for returning orders or large orders.

Lost Wax Molding Process 

Surface roughness of lost-wax casting is significantly smoother than that of sand casting, making it ideal for complex geometries, and it produces a seamless, single-piece mold without a parting line. Lost wax is, however, limited to small sized products with less than 50 kg weight. We also have a small sub-group of lost wax foundries in our foundry group. Our client projects for lost wax casting are turbine blades, medical implants, and aerospace valves.

How to Make Steel Casting Patterns with 3D Files

Reverse engineering & drawing designing process is used for steel castings without drawings. We examine the physical part, process a 3D scan, and then use a finite element analysis program (FEA) to design predictive computational models of both the casting and the pattern. We then pull up a 3D CAD model and review an analysis report to examine the casting and its pattern design.

Our steel casting plan and wood pattern design is done in cooperation between casting engineers and the advisory R&D engineers to come up with a design free of cracks, shrinks, and internal pores.

Wooden patterns are CNC machined up to thickness of 100um. The casting patterns and steel castings are examined for their shrinkage rate by section.

Steel Casting Melting Process

The melting process of industrial steel casting production starts with alloy designing process, where material engineer analyzes the amount of ferrous materials and scraps to come up with the required chemical composition of the casting. We use certified ferrous materials and scraps to melt in our melting furnace. The scrap melting process is followed by a degassing process using Ca-Si or Fe-Ti based deoxiders.

Steel Casting Chemical Composition Check

To obtain a high quality steel casting, before steel casting is poured out in mass-scale, a small sample casting is poured out, polished and sent in for a spectroanalysis. The chemical composition result is compared against the target chemical composition of required steel grade. Once this sample casting’s spectroanalysis is approved, we proceed to the pouring process. Finished castings are sent in for a Y block tensile check.

Steel Casting NDE Quality Testing

Our industrial steel casting foundry provides and suggest wide range of quality inspection methods to clients depending on their priority. For instance, for customers that are more cost sensitive, but seeking castings that are not used in critical applications, our engineers evaluate the need for vigorous quality examination. For steel castings that are required in critical environment, we might recommend a more vigorous quality examination than what the customer has requested if it is required to confirm that the final castings meet the required quality.

Some of our nondestructive quality inspection methods include:

• PT Test (Penetrant Testing)
• LP Test (Liquid Penetrant Testing)
• RT (Radiographic Testing)

Our regular quality examination methods include:

• Mechanical Properties Testing: Tensile Test, Hardness Test, Charpy Impact Testing
• Corrosion Test: Salt Spray Corrosion Test using 5% NaCl Solution and examining degree of corrosion every 168 hours (1 week)

Pump Cast Parts Quality Control & Inspection System

We maintain a rigorous 9-step quality assurance framework across the entire sand-casting process, from raw material verification to non-destructive testing (NDT), ensuring zero-defect manufacturing and full compliance with international standards.

1. Receiving & Raw Material Inspection

• • Check Points: Spectrochemical chemical analysis and raw material visual inspection.
  • Measurement Equipment: Optical Emission Spectrometer.

2. Pattern Making & Design Verification

• • Check Points: Precision dimensional verification, gating system layout, and casting design parameters.
  • Measurement Equipment: Z-Cast analysis equipment and vernier calipers.

3. Melting Quality Control

• • Check Points: Charge material ratio validation, melt temperature monitoring, and chemistry verification.
  • Measurement Equipment: Optical Emission Spectrometer and Immersion Pyrometer.

4. Mold & Core Fabrication

• • Check Points: Sand mixture ratio, sand properties, mold surface hardness, mold dimensions, and visual inspection.
  • Measurement Equipment: Sand tester, digital scales, heating furnace, and vernier calipers.

5. Tapping Control

• • Check Points: Tapping temperature, melt weight, and degassing parameters.
  • Measurement Equipment: Immersion Pyrometer.

6. Pouring Management

• • Check Points: Pouring temperature, pouring time, and complete slag removal.
  • Measurement Equipment: Immersion Pyrometer.

7. In-Process Intermediate Inspection

• • Check Points: As-cast visual inspection, surface finish condition, and geometry/shape verification.
  • Measurement Equipment: MSS-SP-55 Surface Roughness Comparison Specimens and vernier calipers.

8. Heat Treatment Validation

• • Check Points: Furnace loading temperature, heating rate, holding temperature, holding duration, and cooling method monitoring.
  • Documentation: Formal Inspection Certificates.

9. Final Comprehensive Testing

• • Check Points: Final appearance, precision dimensional check, mechanical properties, hardness testing, corrosion resistance (optional), microstructure analysis (optional), ferrite content (optional), and impact strength (optional).
  • NDT Capabilities (Optional): Penetrant Testing (PT), Magnetic Particle Testing (MT), Ultrasonic Testing (UT), and Radiographic Testing (RT).
  • Measurement Equipment: Universal Testing Machine (UTM), Hardness Testers, Microscope, Ferrite Tester, Impact Tester, NDT Testers, and vernier calipers.

High-Volume Steel Casting & Defect-Free End Bells for Steel Mill

Executive Summary

Project Scope: High-volume, end-to-end production of Steel  Casting End Bells for a major US steel mill project—encompassing pattern fabrication, advanced mold preparation, foundry casting, multi-stage precision machining, 100% NDT inspection, and export packaging.

Solutions: Executed an aggressive delivery schedule that competing foundries turned down, achieved through granular daily throughput planning, specialized mold material engineering, and zero-defect quality control.

Delivered 100% compliant, defect-free castings meeting strict NF EN 1371-1 Liquid Penetrant (LP) Testing requirements, eliminating downstream assembly delays for high-duty steel mill operations.

Technical & Quality Standard

Manufacturing & Machining Process

Daily Schedule Management

To guarantee on-time delivery under an aggressive deadline, a detailed day-by-day throughput schedule was shared with the client, tracking daily targets across every phase:

Pattern Fab ⟶ Ceramic/Resin Mold Assembly ⟶ Steel Pouring
⟶ Rough/Finish Machining ⟶ 100% LP Inspection ⟶ Vacuum Packaging

Advanced Molding & Core Setup

To withstand extreme molten steel pouring temperatures (~1, 550∘C) without thermal degradation:

• • Ceramic-Resin Core Integration: Placed high-refractoriness ceramic-resin cores at critical internal bore and passage locations to resist metal wash and prevent sand burning/erosion.

• • Resin Sand Molding: Utilized rigid, self-hardening resin sand molds to maintain dimensional stability and prevent mold wall movement during pouring

Machining & Finishing Process

1. Rough Turning & Datum Setup: Initial heavy turning on large-capacity lathes to remove raw casting scale (– depth of cut) and establish clean reference datums while exposing sub-surface defects early.
2. Intermediate Surface Inspection: Initial LP inspection on rough-machined surfaces to verify weld prep zones (SP3 / CP3 standard) before finish-cutting.
3. Precision Finish Machining (Boring M/C & Vertical MCT): Precision-faced and bored on heavy Horizontal/Vertical Boring Mills (Hyundai WIA / Shibaura KBN series) to lock in tight concentricity. Bolt-circle hole patterns and counterbores were drilled and tapped on Vertical MCTs (Hyundai WIA VX750M / KV600N) in a single setup.

Stringent Quality Assurance & Documentation

• Nuclear/Heavy-Industry Level NDT: Executing 100% LP testing to NF EN 1371-1 (LP3/AP3) far exceeds standard US commercial casting practices (such as ASTM E165 spot-checks), eliminating tool breakage risks during final machining and preventing operational failures under extreme loads.

• Complete QA Shipping Dossier: Each overseas shipment was accompanied by a full quality compliance package:
  1. Inspection Report
  2. Mill Sheet
  3. LP Test Report
  4. 3rd Party Heat Treatment Certificate

   

USKoreaHotlink Key Advantages

• Zero Inclusion Defect Guarantee: Combining ceramic-resin core technology with self-hardening sand molds virtually eliminated sand inclusions, delivering pristine surface quality required for strict LP3/AP3 acceptance.

• Schedule Risk Elimination: Disciplined daily project management allowed the US client to meet a critical mill overhaul deadline.

• Reduced Assembly Prep Time: Applying a low-viscosity anti-rust oil enabled immediate, effortless solvent cleanup at the client’s shop.

• Zero Freight Damage Guarantee: Combining individual vacuum sealing, thin anti-corrosion coating, and export-grade wooden crating ensured 100% corrosion-free delivery across long-distance ocean transport.

End-to-End Manufacturing & High-Precision Machining of Heavy CF8M Pump Components for Power Generation

Executive Summary

Project Scope: Complete end-to-end production from patternmaking and casting to precision finish-machining and final inspection for critical rotating equipment components in power generation pumps:

• CF8M Stainless Steel Diffuser: 1,238 Kg

• CF8M Stainless Steel Suction Bell: 466 Kg

Solutions: turnaround lead time was 80 days, covering pattern fabrication, foundry casting, VTL/radial machining, and quality assurance inspection.

Delivered full traceability and quality compliance under EN 10204 Type 3.1 Certification, managing stress distortion and tight GD&T tolerances on a large austenitic stainless steel cast diffuser.

Technical & Quality Standard

Manufacturing Process

80-Day Production Workflow

Our facility managed a tight 80-day delivery window by having a pattern shop, casting foundries and a machining shop under one roof:

Machining Process

• Diffuser (1,238 Kg) & Suction Bell (466 Kg) Turning: Precision-turned using heavy-duty vertical turning machines with capacities up to  to absorb cutting loads and prevent tool vibration on work-hardening CF8M.

• Deep Hole & Flange Drilling: Executed on a radial drilling machine (2,500 mm swing) for accurate bolting and angular positioning.

Distortion & Quality Controls

1. Stress-Relief Machining Sequences: Managed residual thermal and mechanical stress on the  Suction Bell to eliminate post-machining warpage and out-of-roundness.
2. Standardized QA Audit: Applied ISO 8062 and ISO 2768 standards across all un-specified tolerances to maintain strict quality control prior to final certification sign-off.

USKoreaHotlink Key Advantages

• 80-Day Lead Time: Consolidating patternmaking, casting, machining, and inspection in-house reduces project management overhead and overall procurement cycle times for pump OEMs and pump maintenance and repair shops.

• Regulatory Compliance: Delivery with an EN 10204 3.1 Inspection Certificate provides full auditability required by power plant owners and EPC contractors.

• Quality Control: Strict adherence to ISO 2768 Class K/m tolerances and hundredth-millimeter fit quality guarantee for machining.