1. Hardness is present ex-works and does not rely on impact hardening
High-manganese steel requires significant impact to harden; chromium-molybdenum alloy steel achieves stable hardness upon completion of heat treatment. It delivers consistent wear resistance under conditions of moderate impact and moderate grinding, avoiding rapid wear due to insufficient impact. It is used as a substitute for high-manganese steel in many applications, such as the first compartment of ball mills and semi-autogenous grinding mills, with a service life typically 1.5 2.5 times that of standard ZGMn13.
2. Balanced strength and toughness, with excellent resistance to fracture, spalling and plastic deformation
Its toughness far exceeds that of high-chromium cast iron; it is less prone to chipping, cracking or complete fracture when struck by large chunks of material, thereby reducing the risk of machine jamming caused by broken fragments;
Its yield strength exceeds that of high-manganese steel, providing strong resistance to bulging and compressive deformation; during long-term operation, the liners are less prone to plastic bulging and bolt holes are less likely to tear, thereby reducing liner loosening and material leakage;
It exhibits excellent fatigue performance; under repeated alternating impact wear, it is resistant to fatigue spalling, making it suitable for prolonged continuous operation in mining and cement production lines.
3. Synergistic effects of chromium and molybdenum alloys
Cr: Enhances matrix hardness and hardenability; improves resistance to corrosion by weak slurries; and enhances resistance to abrasive wear;
Mo: Suppresses temper brittleness, ensuring uniform hardness throughout thick and large liners and preventing the core of thick sections from softening; improves high-temperature stability, with minimal performance degradation during short-term temperature spikes;
The rare-earth-modified version further refines grain boundaries, reduces casting microcracks and further enhances impact fatigue life.
4. Good weldability (compared to high-manganese steel and high-chromium cast iron)
Allows for local repair welding and on-site correction, offering greater convenience in installation and maintenance than high-manganese steel (welding of which is strictly prohibited) and high-chromium cast iron;
5. Stable performance in thick sections
For thick liners (60–120 mm), the good hardenability of Cr–Mo ensures minimal hardness variation between the surface and core; thick high-manganese steel components are prone to insufficient core properties when water-hardened, whilst thick high-chromium cast iron components are more susceptible to casting cracks.
6. Wide adaptability to operating conditions, catering to both impact and abrasive wear
In wet grinding slurry environments, it offers superior corrosion resistance to standard high-manganese steel; it is better suited to moderate-temperature operating conditions than high-manganese steel.
7. Comprehensive economic advantages
Whilst the procurement cost is higher than that of standard high-manganese steel, the extended service life reduces replacement frequency, thereby lowering costs associated with downtime and labour for dismantling and installation; In many medium-impact operating conditions, the total life-cycle cost is lower than that of high-manganese steel.
8. Strong customisation capabilities
Can produce various lift bars, end liners, grid plates and pressure strips to drawing specifications; the carbon-chromium-molybdenum ratio can be adjusted to produce versions with a higher emphasis on toughness or wear resistance, to suit different ore hardnesses.
Recommended Applications
Lining plates for the first compartment of ball mill coarse grinding, feed-end lining plates and lift bars (moderate impact; mills where the impact energy is insufficient to fully harden high-manganese steel)
SAG mill lift bars and end lining plates (where there is a desire to avoid the risk of high-chromium cast iron fracture whilst achieving a longer service life than high-manganese steel)
Rod mill liners (line contact impact from rods; chromium-molybdenum alloy steel is highly suitable)
Protective plates for small and medium-sized crushers, and areas of chutes subject to moderate impact
Cement and mining industries; medium to medium-high hardness ores such as iron ore and limestone
Reduces the frequency of downtime caused by liner breakage, thereby minimising downtime losses;
Reduces the frequency of spare part consumption, lowering labour costs for disassembly and reassembly;
Enhances protection of the mill shell, indirectly safeguarding the shell structure and extending the service life of the main unit.
