Especificações principais
- Alloy Types
- CF8M (316 equiv.), CD4MCu Duplex, CE8MN Super Duplex
- PRE Range
- 24 (CF8M) to 42+ (Super Duplex CE8MN)
- Hardness Range
- 140–310 HB (metallic), 40–65 Shore A (rubber)
- pH Capability
- Down to pH < 1 (rubber-lined), pH 3–7 (metallic alloys)
- Chloride Resistance
- >100 mg/L Cl- (super duplex CE8MN)
- Max Temperature
- 70 C (rubber), 300 C (super duplex)
- Applications
- Acid leach pumps, seawater systems, phosphate crushers
- Testing Methods
- Immersion coupon, potentiodynamic polarisation, slurry pot E-C
Corrosion-Resistant Alloys for Crusher and Pump Wear Parts
Standard high-chrome white irons (ASTM A532 Class II and III) and manganese steels (ASTM A128) perform well in dry or near-neutral crushing duties, but they degrade rapidly when exposed to acidic slurries, chloride-bearing waters, or chemically aggressive process streams. In these environments, electrochemical corrosion attacks the metal surface continuously while abrasive particles strip away the protective passive film, creating an erosion-corrosion synergy that accelerates material loss far beyond what either mechanism would produce alone. The freshly exposed bare metal after each particle impact corrodes at rates orders of magnitude higher than the passivated surface, and the resulting soft corrosion products are more easily removed by subsequent impacts, establishing a self-reinforcing degradation cycle. Material loss rates in acidic slurry service (pH 2–4 with 10–30% solids) can be 3–10 times higher than in equivalent dry crushing duties using the same alloy, making standard wear materials uneconomical in these applications.
Corrosion-resistant alloys address the erosion-corrosion synergy by combining controlled chromium (18–27%), molybdenum (2–4%), and nickel (5–25%) additions to stabilise a passive Cr2O3/MoO3 oxide film that reforms rapidly—within milliseconds—after abrasive particle damage. The rate of passive film re-healing, quantified by the repassivation potential measured through potentiodynamic polarisation testing, is the critical parameter that determines whether an alloy can survive in a given erosion-corrosion environment. For crusher liners, pump casings and impellers, slurry valve components, and pipeline wear segments operating in wet acidic conditions, the correct alloy selection depends on the pH range (under normal and upset conditions), chloride ion concentration (which drives pitting corrosion risk, assessed via the Pitting Resistance Equivalent Number or PRE), slurry temperature, and the size, hardness, and angularity of the abrasive particles. ATF supplies cast corrosion-resistant wear parts in CF8M austenitic stainless (PRE ~24), CD4MCu duplex (PRE ~34), CE8MN super duplex (PRE 42+), molybdenum-modified high-chrome irons (25Cr3Mo), and rubber-lined configurations (40–65 Shore A natural rubber or chloroprene) to match the full spectrum of corrosive service conditions.
Key Features of Corrosion-Resistant Wear Parts
Erosion-Corrosion Synergy Control
Alloys are selected to maintain a stable passive film under abrasive contact. Molybdenum and nitrogen additions accelerate passive film reformation after particle impact, reducing the window of bare-metal exposure to corrosive media and breaking the erosion-corrosion cycle that destroys conventional alloys.
pH-Range-Specific Material Selection
Material recommendations are matched to the operating pH range. Mild corrosion duties (pH 5-7) are served by CF8M-type austenitic stainless castings. Moderate acid service (pH 3-5) requires duplex grades with higher chromium and molybdenum. Severe acid duties below pH 3 call for super duplex or rubber-lined configurations.
Chloride Pitting Resistance
Chloride ions penetrate the passive film and initiate pitting corrosion, particularly at elevated temperatures. Super duplex alloys with a Pitting Resistance Equivalent Number (PRE) above 40 are specified for chloride-bearing slurries, seawater-cooled systems, and brine-contact applications where standard austenitic grades fail by pitting.
Duplex Microstructure Advantage
Duplex stainless steels combine approximately equal proportions of austenite and ferrite phases. This dual-phase microstructure provides roughly twice the yield strength of equivalent austenitic grades, improving resistance to cavitation erosion and high-velocity particle impact while maintaining corrosion resistance.
Rubber-Lined Composite Option
For severe acid duties where no metallic alloy provides adequate corrosion resistance at reasonable cost, natural rubber or chloroprene rubber linings bonded to a carbon steel shell offer a proven alternative. Rubber absorbs impact energy and resists chemical attack, with the metal shell providing structural support.
Application-Matched Alloy Engineering
Each corrosion-resistant wear part is specified based on a complete review of the service environment: slurry pH, chloride content, temperature, abrasive particle size, flow velocity, and impact energy. This prevents both under-specification (premature failure) and over-specification (unnecessary material cost).
Corrosion-Resistant Alloy Comparison
The following table compares the principal alloy options for corrosive wear service. Selection depends on the pH range, chloride level, temperature, and the severity of abrasive wear. The corrosion resistance rating indicates performance in acidic slurry environments, not purely chemical immersion resistance.
| Material | Dureza | Aplicação | Notas |
|---|---|---|---|
| CF8M (316 Stainless Equivalent) | 140-190 HB | Mild corrosion (pH 5-7) with light abrasion. Slurry pump casings, valve bodies, and screen frames in near-neutral wet processing | PRE ~24. Adequate for low-chloride, near-neutral slurries. Poor pitting resistance above 40mg/L Cl- |
| CD4MCu (Duplex Stainless) | 230-290 HB | Moderate acid service (pH 3-5) with medium abrasion. Phosphate slurry crushers, wet scrubber internals, acidic tailings pumps | PRE ~34. Approximately 2x yield strength of CF8M. Good resistance to erosion-corrosion in moderate acid |
| CE8MN (Super Duplex) | 250-310 HB | Severe acid and chloride service (pH <3 or >100mg/L Cl-). Seawater-cooled crushers, brine processing, acid mine drainage handling | PRE ~42. Best metallic option for combined chloride pitting and acid corrosion in abrasive slurry |
| High-Cr Iron + Mo (25Cr3Mo) | 600-680 HB | Moderate acid (pH 3-5) with heavy abrasion. Crusher liners and grinding media where abrasion dominates over corrosion | Molybdenum addition improves passive film stability. Sacrifices some corrosion resistance for higher abrasion resistance |
| Natural Rubber Lining (40-65 Shore A) | N/A (40-65 Shore A) | Severe acid duty (pH <3) with fine abrasive particles. Acid leach circuit pumps, chemical plant pipe bends, HCl/H2SO4 slurry service | Excellent chemical resistance to most mineral acids. Limited to temperatures below 70C and particle sizes below 10mm |
CF8M (316 Stainless Equivalent)
CD4MCu (Duplex Stainless)
CE8MN (Super Duplex)
High-Cr Iron + Mo (25Cr3Mo)
Natural Rubber Lining (40-65 Shore A)
PRE = Pitting Resistance Equivalent Number, calculated as %Cr + 3.3(%Mo) + 16(%N). Higher PRE indicates greater resistance to chloride pitting. Hardness values are as-cast; post-weld or service-exposed hardness may vary.
Need Corrosion-Resistant Wear Parts for Your Application?
Provide your slurry chemistry, pH range, chloride level, and operating temperature. ATF engineering will recommend the optimal alloy and supply a quotation for your specific corrosive-wear duty.
Applications by Service Environment
Corrosion-resistant alloys are specified by the chemical environment rather than by equipment brand. The following service environments represent the most common applications for corrosion-resistant crusher and pump wear parts. Each environment presents a distinct combination of pH, chloride content, temperature, and abrasive loading that determines the alloy selection.
Acidic Slurry Processing
- Crusher liners and pump impellers in sulphuric acid leach circuits (pH 1-3)
- Screen panels and chute liners handling acidified process water with suspended solids
- Agitator impellers and tank internals in acid-contacted mineral slurry
Seawater / Chloride Service
- Seawater-cooled crusher bearing housings and seal components
- Desalination plant intake screen frames and pump casings handling sand-laden seawater
- Brine circuit crushers and classifiers in potash and salt processing
Phosphate / Fertilizer Plants
- Phosphate rock crushers exposed to phosphoric acid mist and wet acidic fines
- Slurry pump casings handling phosphogypsum slurry (pH 2-4, fluoride-bearing)
- Granulator crusher liners in contact with ammonium nitrate or urea process liquor
Acidic Mine Water
- Acid mine drainage (AMD) pump impellers and casings (pH 2-4, high dissolved metals)
- Tailings dam reclaim pump liners handling oxidised pyritic slurry
- Crusher components in heap leach operations with sulphuric acid irrigation
Chemical Plant Crushing
- Size reduction equipment for chemical intermediates with residual acid contamination
- Catalyst crushing and screening components exposed to hydrochloric or nitric acid vapour
- Wet scrubber internals handling chemically aggressive particulate-laden gas streams
Corrosion-Resistant Perguntas frequentes
Encontre respostas para perguntas comuns sobre corrosion-resistant materiais, seleção, manutenção e pedidos. Não encontrou o que procura?
Contatar nossa equipeHow does erosion-corrosion synergy accelerate wear compared to pure abrasion or pure corrosion alone?
When should rubber lining be used instead of a corrosion-resistant metal alloy?
What is the Pitting Resistance Equivalent Number (PRE) and why does it matter for chloride service?
How is the correct corrosion-resistant alloy selected for a specific application?
Can corrosion-resistant alloys match the abrasion resistance of standard high-chrome white iron?
What testing methods are used to validate corrosion-resistant alloy selection?
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Solve Corrosive Wear with the Right Alloy
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