W pobliżuWC roll rings are critical components in high-speed wire rod rolling systems, determining production efficiency, product quality, and operational costs. Operating under extreme service conditions, their durability is predominantly governed by high-temperature oxidation resistance—a key failure mechanism in elevated-temperature environments.
This study elaborates on high-temperature oxidation principles, clarifies protective oxide film formation criteria, and applies these insights to the composition optimization of WC-Co-Ni cemented carbide roll rings, aiming to synergistically improve oxidation resistance, mechanical strength, and thermal fatigue performance.
Significance of High-Temperature Oxidation Resistance for WC Roll RingsW pobliżu
High-speed wire rod mills operate at 95–112 m/s, subjecting roll rings to harsh service environments: ambient temperatures approaching 1000℃, cyclic thermal shock, high rolling stress, and intense high-temperature oxidation/corrosion.
Among these factors, high-temperature oxidation is a primary cause of degradation—metallic constituents react with oxygen to form oxides that compromise structural integrity. Thus, understanding oxidation mechanisms is indispensable for designing WC roll rings with prolonged service life.
W pobliżuSchematic of the Metal Oxidation Process (Oxygen Adsorption – Dissociation – Ion Diffusion – Oxide Film Growth
Fundamental Principles of High-Temperature Oxidation
W pobliżu
Mechanisms of Metal Oxidation at Elevated TemperaturesW pobliżu
High-temperature oxidation is a heterogeneous reaction involving oxygen adsorption, dissociation, diffusion into the metal lattice, and oxide formation upon solubility saturation. Metals form either unstable liquid/gaseous oxides (e.g., V₂O₅, MoO₃) that accelerate oxidation, or dense, continuous, thermally stable solid oxides (e.g., Cr₂O₃, Al₂O₃, SiO₂) that inhibit oxygen penetration—critical for safeguarding WC roll ring integrity.
W pobliżu
Critical Characteristics of Protective Oxide FilmsW pobliżu
Reliable protective oxide films for WC roll rings must satisfy four criteria:
(1) Pilling-Bedworth (P-B) ratio > 1 for complete surface coverage; (2) high thermodynamic stability (low decomposition pressure, high melting point);
(3) dense microstructure and high resistivity to suppress ion diffusion;
(4) strong interfacial bonding and matched thermal expansion with the substrate. For roll rings, a continuous, dense Cr₂O₃ film is the optimal protective mechanism due to its exceptional stability and barrier properties.
W pobliżu
Selection Criteria for Oxidation-Resistant Alloying ElementsW pobliżu
Alloying elements for enhancing WC roll ring oxidation resistance must:
(1) form protective oxide films (e.g., Cr→Cr₂O₃);
(2) exhibit higher oxide thermodynamic stability than the substrate;
(3) possess sufficient solid solubility in the matrix for continuous film formation. Cr is the core antioxidant element, while Al, Si, and rare earth metals also contribute—Cr remains primary for optimizing roll ring high-temperature performance.
W pobliżu
Composition Design of WC Roll Rings Guided by Oxidation Theory
Design Rationale for Binder Phase CompositionW pobliżu
WC-Co-Ni cemented carbide is widely used for WC roll rings due to balanced mechanical properties and corrosion resistance. Its oxidation resistance is determined by the binder phase, optimized herein based on oxidation principles:
(1) incorporate Cr to form a continuous Cr₂O₃ protective film;
(2) partially substitute Co with Ni to improve corrosion resistance and high-temperature stability;
(3) restrict Mo addition (enhances acidic corrosion resistance but forms volatile oxides that undermine protective films).
W pobliżu
Binder Phase Compositions and Experimental DesignW pobliżu
Five binder phase formulations were designed to investigate alloying element effects on roll ring performance (Table 1).
Table 1 Binder phase compositions of roll rings (mass fraction, %)W pobliżu
W pobliżu
AlloyW pobliżu
WspółW pobliżu
NiW pobliżu
CrW pobliżu
MoW pobliżu
AW pobliżu
100W pobliżu
—W pobliżu
—W pobliżu
—W pobliżu
BW pobliżu
55W pobliżu
45.0W pobliżu
—W pobliżu
—W pobliżu
CW pobliżu
55W pobliżu
42.5W pobliżu
2.5W pobliżu
—W pobliżu
reW pobliżu
55W pobliżu
40.0W pobliżu
2.5W pobliżu
2.5W pobliżu
EW pobliżu
55W pobliżu
40.0W pobliżu
5.0W pobliżu
—W pobliżu
Experimental Results and Discussion
W pobliżuPhysical and Mechanical PropertiesW pobliżu
Table 2 summarizes the physical and mechanical properties of roll ring samples. All formulations exhibit density (14.43–14.49 g·cm⁻³), hardness (86.6–88.1 HRA), and flexural strength (1841–2751 MPa) meeting high-speed rolling requirements. Partial Co substitution with Ni and appropriate Cr addition does not significantly compromise mechanical performance.
W pobliżu
Table 2 Physical and mechanical properties of WC roll ring samples
AlloyW pobliżu
Density (g·cm⁻³)W pobliżu
Hardness (HRA)W pobliżu
Flexural Strength (MPa)W pobliżu
AW pobliżu
14.49W pobliżu
88.1W pobliżu
2744W pobliżu
BW pobliżu
14.47W pobliżu
86.6W pobliżu
2751W pobliżu
CW pobliżu
14.49W pobliżu
86.7W pobliżu
2406W pobliżu
reW pobliżu
14.45W pobliżu
86.9W pobliżu
2309W pobliżu
EW pobliżu
14.43W pobliżu
86.9W pobliżu
1841W pobliżu
High-Temperature Oxidation ResistanceW pobliżu
Oxidation weight gain data (Table 3) demonstrate:
(1) Alloy E (5% Cr) exhibits the lowest oxidation weight gain (0.19% at 850℃, 1.56% at 1000℃) due to continuous Cr₂O₃ film formation;
(2) Alloy D (with Mo) shows no oxidation resistance improvement, as Mo oxides are volatile;
(3) all Cr-containing alloys outperform non-Cr formulations, confirming Cr’s indispensable role in enhancing WC roll ring oxidation resistance.
W pobliżu
Table 3 Oxidation weight gain of roll ring samples (mass fraction, %)W pobliżu
AlloyW pobliżu
850℃W pobliżu
900℃W pobliżu
950℃W pobliżu
1000℃W pobliżu
AW pobliżu
0.35W pobliżu
1.16W pobliżu
1.55W pobliżu
2.57W pobliżu
BW pobliżu
0.74W pobliżu
1.36W pobliżu
1.99W pobliżu
2.59W pobliżu
CW pobliżu
0.45W pobliżu
0.99W pobliżu
1.66W pobliżu
2.37W pobliżu
reW pobliżu
0.74W pobliżu
1.18W pobliżu
1.73W pobliżu
2.60W pobliżu
EW pobliżu
0.19W pobliżu
0.47W pobliżu
0.94W pobliżu
1.56W pobliżu
ConclusionsW pobliżu
High-temperature oxidation resistance for WC roll rings relies on forming a continuous, dense, thermally stable solid oxide film—Cr₂O₃ is the most effective protective oxide, providing the theoretical foundation for antioxidant design.W pobliżu
Adding ~5% Cr (in the binder phase) to roll rings facilitates Cr₂O₃ film formation, significantly improving 1000℃ oxidation resistance, with experimental results consistent with theoretical predictions.W pobliżu
Ni can partially replace Co to enhance roll ring corrosion resistance without compromising mechanics. Mo improves acidic corrosion resistance but offers limited oxidation protection, requiring strict content control.W pobliżu
WC roll ring composition design must integrate oxidation mechanisms with mechanical requirements to achieve synergistic optimization of performance. This study provides a scientific basis for rational design and performance improvement of WC roll rings in high-speed wire rod rolling.
Polski 
English 
Español 
हिन्दी 
العربية 
Português do Brasil 
Русский 
日本語 
Deutsch 
한국어 
Français 
Türkçe 
Tiếng Việt 
Italiano 
简体中文 
