AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

Green Sand Control Equipment – Hot

Compression Strength

Scott M. StroblSimpson Technologies Corporation

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

• Are there methods that can better quantify molding sand properties to assist in the preparation of quality molds and defect free castings?

• Standard green sand test are within specifications, yet we experience sand related problems.

• Search for an illusive sand property– Hot compression strength (elevated temperatures)

Introduction

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

Agenda• High temperature compression strength

test– Application to casting defects– Discuss test procedure and instrument– Review strength-deformation plot– Review some sand and process variables that

can influence hot compression strength– Case study – hot compression strength

• Muller / Mixer sand comparison – HCS and GCS

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

AFS Core and Mold Process Control• Elevated temperature sand properties

– hot compressive strength

- “Hot strength is more of a measure of the nature and quality of the clay present than any other factor.”

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

AFS – Casting Defects Hand BookReferences to molding sand strength and deformation

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

Casting Defects

• Sand inclusions• Swells • Mold erosion• Expansion defects • Broken or cracked castings

– Collapsibility

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

High Temperature Compression and Deformation Instrument

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

2 in

Sample Preparation

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

Hot Compression and Deformation Test Procedure

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

Strength-Deformation Plot of a Molding Sand

Strength132.0psi

Deformation2.62%

psi

% def.

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

Sand/process variables that can influence HCS

• Clay Type– Sodium bentonite– Calcium bentonite

• MB Clay• Mulling

– Sand preparation process

• Moisture• Compactability• Mold hardness

• Temperature• AFS clay• Carbon additives• Cellulose additives• Cereal additives• Others

Influence can change with testing temperature

AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA

For additional information, please contact:

• Scott Strobl• Simpson Technologies Corporation• 751 Shoreline Drive, Aurora IL 60504• (630) 978 - 0044• sstrobl@simpsongroup.com