ASTM G75-24 PDF

Full title and description

ASTM G75-24 — Standard Test Method for Determination of Slurry Abrasivity (Miller Number) and Slurry Abrasion Response of Materials (SAR Number). This procedure defines laboratory methods to measure the relative abrasivity of slurries (Miller and D2 Numbers) and the abrasion response of candidate materials expressed as SAR Numbers, using standardized wear specimens and controlled slurry circulation conditions.

Abstract

This test method provides a reproducible laboratory technique to rank slurries by abrasivity and to compare material performance in abrasive slurries. Test results are reported as Miller Number (reference 27% chromium iron or optional D2 tool steel reference), D2 Number (alternative reference) and SAR Number (slurry abrasion response of other materials). Results can be used to inform material selection, equipment design (especially pumps and fluid-handling components), and predictive maintenance planning. Typical test duration and specimen preparation requirements are specified to allow consistent mass-loss (converted to volume loss) measurements.

General information

• Status: Active (current edition G75-24).
• Publication date: December 2024 (G75-24 revision published/updated in Dec 2024).
• Publisher: ASTM International.
• ICS / categories: 17.040.20 (properties of surfaces / wear and erosion).
• Edition / version: G75-24 (designation G0075-24; revises ASTM G75-15 series).
• Number of pages: 22 pages.

Scope

This method covers a single laboratory procedure that produces either a Miller Number or a SAR Number for a given slurry. It specifies the use of duplicate standard-shaped wear blocks (27% chromium iron as the primary reference, with an optional D2 tool-steel reference), specimen preparation (flat finished wearing surface for SAR tests), test apparatus, slurry conditioning, run duration (typical SAR test duration described) and mass-loss measurement procedures required to convert mass loss to volume loss and compute the reported indices. The method notes limitations for thin hard coatings and short-duration test runs where consistent rates of mass loss may not be established.

Key topics and requirements

• Definition and calculation of Miller Number, D2 Number and SAR Number (indices of slurry abrasivity and material response).
• Standard reference wear blocks (27% chromium iron) and optional D2 tool steel reference.
• Specimen preparation: requirement for a finished flat wearing surface for SAR tests; limits for thin hard coatings.
• Test apparatus and slurry circulation/conditioning procedures to ensure reproducible abrasive action.
• Duration and data collection: mass-loss measurements converted to volume loss and index calculation (typical guidance on interpretive thresholds — e.g., values ≈50 or lower indicate relatively minor damage for pumping systems).
• Reporting requirements, safety and environmental considerations for handling abrasive slurries.

Typical use and users

Used by materials engineers, corrosion/erosion specialists, metallurgists, mining and mineral processing engineers, pump and slurry-equipment manufacturers, testing laboratories, and R&D teams concerned with slurry transport wear. Typical applications include ranking ore slurries for pump selection, qualifying candidate materials or coatings for slurry-service components, and supporting wear-life predictions and procurement specifications.

Related standards

Related ASTM standards commonly used alongside G75 include ASTM G65 (dry sand/rubber wheel abrasion), ASTM G132 (pin abrasion), ASTM G40 (terminology relating to wear and erosion), and earlier/later revisions of G75 (for historical comparison). Industry test guides and pump-manufacturer test protocols may also reference G75-derived indices when specifying slurry-handling materials.

Keywords

Miller Number, SAR Number, slurry abrasivity, slurry abrasion response, wear blocks, D2 Number, slurry testing, pump wear, abrasive slurries, material ranking.

FAQ

Q: What is this standard?

A: ASTM G75-24 is a laboratory test method that quantifies the abrasivity of slurries (Miller and D2 Numbers) and measures the abrasion response of materials (SAR Number) using standardized wear specimens and controlled slurry test conditions.

Q: What does it cover?

A: It covers specimen types and preparation, reference wear blocks (27% chromium iron and optional D2 tool steel), test apparatus and slurry conditioning, test duration and mass-loss measurement, conversion to volume loss, index calculations (Miller/D2/SAR Numbers), and reporting. It also notes limitations for some coatings and short-duration tests.

Q: Who typically uses it?

A: Materials and corrosion engineers, testing laboratories, mining and mineral-processing companies, pump and slurry-equipment manufacturers, and R&D organizations working on wear-resistant materials and slurry-transport systems.

Q: Is it current or superseded?

A: Current — the G75-24 edition (designation G0075-24) is the active revision released in December 2024 and supersedes prior editions such as G75-15 and earlier versions.

Q: Is it part of a series?

A: It is part of ASTM Committee G02 (Wear and Erosion) publications and sits among related wear and abrasion standards (for example G65, G132 and others). It is published as part of the ASTM Book of Standards (volume for wear/erosion-related methods).

Q: What are the key keywords?

A: Miller Number, SAR Number, D2 Number, slurry abrasivity, abrasion testing, wear blocks, slurry wear, pump-material selection.