Alloy Wet Sand Rubber Wheel Abrasion Wear Evaluation (ASTM G105 Testing)

Alloy wet sand rubber wheel wear evaluation is a standardized laboratory method for quantifying the abrasive wear resistance of metallic materials in wet, slurry-laden service environments. Performed in accordance with ASTM G105, the test measures the mass and volume loss of alloy specimens abraded by a rubber-rimmed wheel running through a controlled sand-water slurry, providing essential data for material selection, quality control, and wear-life prediction in mining, dredging, and slurry handling industries.

Technical Overview

Wet sand rubber wheel abrasion testing, standardized as ASTM G105 (Standard Test Method for Conducting Wet Sand/Rubber Wheel Abrasion Tests), is a widely accepted laboratory procedure for evaluating the resistance of metallic alloys to low-stress, three-body abrasion in the presence of water. During the test, a flat alloy specimen is pressed against a rotating wheel fitted with a chlorobutyl rubber rim of controlled hardness while a sand-water slurry is continuously introduced into the contact zone. The sand particles trapped between the compliant rubber surface and the specimen produce scratching, ploughing, and micro-cutting damage representative of many real-world slurry handling conditions.

Unlike the dry sand rubber wheel test described in ASTM G65, the wet method introduces an aqueous environment that more closely simulates slurry transportation, dredging, mineral processing, and similar applications. The presence of water can also reveal corrosion-assisted wear mechanisms, in which mechanical abrasion and electrochemical degradation act synergistically to accelerate material removal. This makes ASTM G105 particularly valuable for ranking stainless steels, alloy steels, cast irons, hardfacings, and other wear-resistant materials intended for wet service.

The test generates a quantitative measure of wear, normally expressed as adjusted volume loss in cubic millimeters, which is corrected against a certified reference wear block to compensate for batch-to-batch variation in sand aggressiveness. Results are used for material ranking, supplier qualification, research and development of new alloys, and lifetime estimation of components subjected to slurry abrasion. Testing is typically performed by accredited third-party laboratories equipped with calibrated wet sand rubber wheel apparatus and precision gravimetric instrumentation.

Testing Samples

Metallic Alloys

The method is applicable to virtually any metallic alloy that can be prepared as a flat rectangular coupon. Commonly evaluated material families include carbon and low-alloy steels, quenched and tempered wear-resistant steels, austenitic and duplex stainless steels, manganese steels, white cast irons and chrome carbide irons, nickel-based and cobalt-based alloys, hard metals, and castings intended for abrasive slurry service.

Weld Overlays and Thermal Spray Coatings

Hardfaced overlays, welded claddings, and thermally sprayed coatings deposited onto steel substrates can also be evaluated, provided the coating is well adhered, sufficiently thick to prevent the substrate from influencing the result, and can be ground flat. Such testing supports the development and qualification of wear protection solutions for ground engaging tools, chute liners, and pump components.

Specimen Geometry and Preparation

Standard specimens are rectangular flat coupons, typically on the order of 25 mm by 76 mm with a thickness of several millimeters, machined or ground so that the test surface is flat and free of scale, burrs, and machining marks. The test surface is normally ground to a uniform fine finish, and specimens are cleaned, dried, and weighed on an analytical balance with a resolution of 0.1 mg before and after testing. Identical surface preparation must be applied to all specimens within a comparison program, because initial surface condition measurably influences early-stage wear behavior.

Testing Items

A complete wet sand rubber wheel evaluation typically includes the following measured and derived parameters:

• Specimen mass loss, determined gravimetrically to the nearest 0.1 mg after ultrasonic cleaning and drying.
• Volume loss in cubic millimeters, calculated from mass loss using the measured or certified density of the alloy.
• Adjusted volume loss, normalized against the certified loss of the reference wear block to correct for sand batch variability.
• Relative wear resistance, defined as the ratio of reference material wear to specimen wear, used for straightforward material ranking.
• Dimensionless wear coefficient or wear rate, normalized by applied load and sliding distance for engineering calculations.
• Wear scar characterization, including scar depth, width, and surface morphology by optical or scanning electron microscopy when mechanism analysis is required.
• Comparison of wear response across rubber wheel hardness grades of 50, 60, and 70 Shore A, which allows assessment of severity sensitivity.
• Optional corrosion-wear synergy assessment, contrasting mass loss in the wet slurry with equivalent dry conditions per ASTM G65.

Testing Methods

Apparatus and Test Conditions

The test machine consists of a lever-arm loading system, a specimen holder, and a driven wheel approximately 178 mm in diameter carrying a replaceable rubber rim about 12.7 mm wide. Three rims of differing hardness are used: 50, 60, and 70 Shore A durometer, corresponding to the three procedures defined by ASTM G105. A constant load, commonly 22 N (5 lbf), presses the specimen against the wheel, which rotates at a fixed speed in the range of roughly 200 to 250 rpm as specified by the standard. The abrasive medium is a graded silica sand, typically AFS 50-70 test sand, mixed with water to form the slurry that is fed into the wheel-specimen interface. Because slurry abrasion severity generally increases with rubber hardness, the hardest wheel produces the most aggressive condition.

Reference Calibration and Conditioning

Before testing unknown materials, the laboratory conditions the rubber wheel and verifies sand aggressiveness by running a certified reference wear block, generally a standardized tool steel. The measured mass loss of the reference specimen is compared with its certified value, and the resulting correction factor is applied to all specimen results in that test series. This normalization step is a defining feature of ASTM G105 and is essential for achieving inter-laboratory comparability.

Test Procedure

The general sequence of a wet sand rubber wheel test is as follows:

• Clean, dry, and weigh the specimen to the nearest 0.1 mg, and record its dimensions and density.
• Prepare the sand-water slurry using the specified silica sand and water proportions, ensuring consistent batch preparation.
• Clamp the specimen in the holder and apply the specified normal load through the lever arm.
• Run the wheel for the prescribed number of revolutions, with fresh slurry supplied continuously to the contact zone.
• Remove the specimen, rinse and ultrasonically clean it, dry it thoroughly, and reweigh it to determine mass loss.
• Run the certified reference block under identical conditions to establish the sand correction factor.
• Repeat runs as required, typically with intermediate wheel reconditioning, and average replicate results to improve precision.
• Calculate volume loss, apply the reference adjustment, and compute relative wear resistance or wear rate as needed.

Data Reduction and Interpretation

Volume loss is obtained by dividing the measured mass loss by the specimen density. The adjusted volume loss is then calculated by scaling the specimen result with the ratio of the certified to the measured wear of the reference block, thereby compensating for the inherent variability of natural sand abrasives. Lower adjusted volume loss indicates higher abrasion resistance. Because the test reproduces low-stress abrasion in which abrasive particles are not fractured, results should not be extrapolated to high-stress gouging or impact-dominated service without supporting tests such as ASTM B611 or jaw crusher wear assessments. Careful interpretation should also account for the known dependence of wet wear on rubber hardness, slurry composition, and potential corrosion-wear synergy of corrosion-sensitive alloys.

Quality Assurance Considerations

Reliable results depend on strict control of rubber rim condition, sand conditioning and moisture content, water quality, load calibration, and revolution counting. Accredited third-party laboratories maintain these controls through documented procedures, calibrated instrumentation, traceable reference materials, and periodic verification runs. Duplicate or triplicate testing is strongly recommended, since slurry abrasion data typically show wider scatter than dry abrasion data.

Applications

Wet sand rubber wheel wear evaluation supports engineering decisions across a broad range of industries in which components are exposed to abrasive aqueous slurries:

• Mining and mineral processing: ranking of liners, mill components, screens, and launder materials handling ore slurries.
• Dredging: selection of steels, irons, and overlays for cutter heads, suction pipes, and pump wet ends.
• Slurry pumping and pipeline transport: qualification of pump impellers, casings, and internal pipe coatings.
• Oil sands and heavy media processing: evaluation of alloys exposed to highly abrasive sand-laden fluids.
• Construction and earthmoving: development of ground engaging tools, bucket liners, and wear plates for wet ground conditions.
• Agriculture: assessment of tillage tool alloys and coatings operating in wet, abrasive soils.
• Power generation and flue gas desulfurization: material selection for slurry circulation pumps and absorber internals.
• Foundries and welding consumable manufacturers: research, development, and certification of wear-resistant alloys and hardfacing products.

FAQ

What is the difference between ASTM G105 and ASTM G65?

ASTM G105 uses a sand-water slurry and evaluates wear under wet, low-stress, three-body abrasion conditions, whereas ASTM G65 feeds dry sand into the contact zone. The wet test is more representative of slurry handling service and can reveal corrosion-assisted wear in susceptible alloys, while the dry test is preferred for purely abrasive, moisture-free environments. Laboratories often run both tests to separate mechanical and corrosion-related contributions to total wear.

Why does the standard specify three rubber wheel hardnesses?

Rubber rim hardness controls how deeply abrasive particles penetrate the contact interface and therefore the severity of abrasion. Wheels of 50, 60, and 70 Shore A hardness define progressively more aggressive test conditions, allowing engineers to determine whether a material maintains its wear advantage across a range of severities or only under specific conditions.

What sample size is required for testing?

A standard flat coupon of approximately 25 mm by 76 mm, several millimeters thick, is sufficient for each run. Because replicate testing is recommended, clients are typically advised to supply several coupons per material, along with density data or sufficient material for density measurement.

How are results reported and interpreted?

The primary reported result is the adjusted volume loss in cubic millimeters, corrected using a certified reference wear block to normalize sand aggressiveness. Supporting values may include relative wear resistance, wear rate, and scar morphology. A lower adjusted volume loss indicates better slurry abrasion resistance, and comparisons are most meaningful when materials are tested under identical conditions within the same program.

Can welded overlays, coatings, and castings be tested?

Yes. Hardfacings, welded overlays, thermal spray coatings, and cast alloys can all be evaluated, provided the specimen can be prepared flat with adequate coating integrity and thickness. For overlays, care must be taken to ensure that the test surface is uniform and that dilution or surface waviness does not distort the measurement.

How long does a typical evaluation take?

A single test interval is short, generally consisting of several hundred wheel revolutions completed within minutes, but a full program includes wheel conditioning, reference block calibration, replicate runs at one or more wheel hardnesses, and gravimetric analysis. Depending on scope, a complete evaluation with a written report is typically completed within a few working days by an accredited third-party laboratory.