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NovaFlow&Solid CV

NovaFlow&Solid CV - Improved casting quality and strength using casting process

simulation efficiently

Author: Håkan Fransson

Novacast Systems AB Ronneby, Sweden

+46 457465800, info@novacast.se

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NovaFlow&Solid CV

ABSTRACT

NovaFlow&Solid CV can make casting process simulations with much fewer mesh elements, enabling much faster simulations. This allows making more variants of a

specific casting layout and considerably optimizes the casting. The technology enables simulations of virtually any type of casting, even extremely thin-walled or complex. The

meshing method used is Control Volume (CV), which means that the outer shapes of the 3D model restrict the elements. The elements are 100 % flexible and can assume any shape, as well as work properly as fractions of elements. The presentation will cover a

specific casting case where you will see how easily you can check different variants of the same casting layout. It will show the capabilities of the software and how designers can

use the software to improve casting design.

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Presentation Håkan Fransson

NovaFlow&Solid CV

• CEO Novacast Systems AB

• Product Manager NovaFlow&Solid (more than 11 Years)

• 25 years in the foundry business

• 5 years practical experience from HPD

• 4 years practical experience from Gravity casting

Presentation Novacast Systems AB • Swedish company with head office in Ronneby

• Develops NovaFlow&Solid since 1994

• Develops Metallurgical Process Control for cast iron (ATAS)

• Novacast Systems has its origin in “NovaCast AB” founded 1981 by Rudolf Sillén

• Installations in 50 countries with a total of >800 licenses

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Introduction

NovaFlow&Solid CV

• NovaFlow&Solid CV is really fast. Solidification simulations is done in maximum 1 hour but often within minutes, mouldfilling simulations takes from hours up to 24 hours depending on complexity of the simulation.

• Automatic meshing = meshing complete within seconds

• Simulates Mouldfilling, Solidification and stresses

• Simulates all commercial casting methods including all types of

gravity casting, Investment casting, Low Pressure die casting

and High pressure die casting.

• Simulates all commercial materials such as Gray and Ductile

Iron, Steels of all kinds, Aluminium, Magnesium, Zinc, Copper-

Based allloys and Super Alloys.

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NovaFlow&Solid CV Equations/characteristics • Control volumes are used for exact geometry definition (CV method)

• Control volume method combines a structured cubic mesh with fractional cells that can take any shape in order to describe the casting.

• CV method (CVM) is used for solution of heat-mass-transfer equations, phase transitions, equations of stressed-strained state and also free surface transfer

• We take the gravity influence into account during filling and solidification

• Temperature-dependent material properties

• Taking different technological solutions into account (chills, channels, TEHs)

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NovaFlow&Solid CV Equations/characteristics

Pouring Temperature

Start solidification = liqidus

Solidified 100 % = solidus

Cooling down to room temperature

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NovaFlow&Solid CV

Border cells describe the surface and cubic cells are used when the cells are not effected by the boundary

Control volume - Meshing

One cell can contain different materials

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• The casting has defects • Design creates hot spots which are hard to feed • Simulation of casting only to determine weak points • Calculating feeders within the software • Simulation of chills and feeders

Problem definition

NovaFlow&Solid CV

• Cast material: Low alloyed Steel (Liquidus: 1512; Solidus: 1477)

• Mould material: Furan sand • Sleeve material: Exo_Cal = Exothermic material

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NovaFlow&Solid CV Four different simulation variants

Case 1 – Casting only Case 2 – Casting with feeders

Case 3 – Casting with feeders no core Case 4 – Casting with feeders and core

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Analysis

NovaFlow&Solid CV

• 500 000 Mesh elements used for calculation • Solidification simulation only • Gravity influence according to steel solidification • Results: temperatures, liquid phase fraction, solidification time and micro and macro shrinkages • Can also calculate SDAS; Brinell hardness and Tensile strength

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NovaFlow&Solid CV Liquid phase fraction - Case 1

Case 1 Case 2

Case 3 Case 4

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NovaFlow&Solid CV Liquid phase fraction - Case 2

Case 1 Case 2

Case 3 Case 4

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NovaFlow&Solid CV Liquid phase fraction - Case 3

Case 1 Case 2

Case 3 Case 4

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NovaFlow&Solid CV Liquid phase fraction - Case 4

Case 1 Case 2

Case 3 Case 4

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NovaFlow&Solid CV Shrinkage prediction of case 1

Case 1 Case 2

Case 3 Case 4

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NovaFlow&Solid CV Shrinkage prediction of case 2

Case 1 Case 2

Case 3 Case 4

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NovaFlow&Solid CV Shrinkage prediction of case 3

Case 1 Case 2

Case 3 Case 4

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NovaFlow&Solid CV Shrinkage prediction of case 4

Case 1 Case 2

Case 3 Case 4

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Calculating feeder

NovaFlow&Solid CV

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SDAS = Secondary dendrite arm spacing

NovaFlow&Solid CV

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Conclusions

NovaFlow&Solid CV

• Optimize ýyour casting design • Find the best solution to cast it (Calculate feeders) • Optimize casting yield (Casting weight/total weight) • Avoid problems in production • Reduce costs by optimizing the casting for production • Optimize the strength of the casting (SDAS; STRESS calc...)

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Figures and plots

NovaFlow&Solid CV

Simulation results numerical • nnn

Case Casting yield %

Total Weight Solidification time

Calculation time

No 1 - 50.00 kg 6.01 minutes 1.5 minutes

No 2 88 % 56.45 kg 24.52 minutes 2 minutes

No 3 79 % 62.89 kg 25.50 minutes 2 minutes

No 4 81 % 61.90 kg 25.50 minutes 2 minutes

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Q & A, Thank you

NovaFlow&Solid CV