What Is NM600 Wear-Resistant Steel Plate?
NM600 is a high-strength, abrasion-resistant steel plate produced by quenching and tempering, with the designation NM meaning wear-resistant steel in Chinese and 600 referring to the nominal Brinell hardness of about 600 HBW. The grade is designed for extreme durability in mining, construction, and material handling, where components see severe sliding abrasion and impact. It is supplied under the Chinese NM series practice and the Brinell hardness is measured per EN ISO 6506-1, with typical hardness of about 570-640 HBW.
Chemical Composition
The typical chemical composition of NM600 is carefully balanced for hardenability and toughness. Maximum or range values (percent by mass) are carbon 0.47, silicon 0.70, manganese 1.60, phosphorus 0.025, sulfur 0.010, chromium 0.50-1.20, nickel 1.50, molybdenum 0.60, boron 0.0005-0.0060, aluminum 0.015 minimum, titanium 0.15, and vanadium 0.20. The chromium and molybdenum additions provide hardenability and tempering resistance, nickel supports toughness, and the boron addition ensures through-hardening of thicker sections during quenching.
Mechanical Properties
The defining property of NM600 is its hardness of approximately 570-640 HBW. The product table lists tensile strength of 1850-2150 MPa, yield strength of 1350 MPa minimum, elongation of 7% minimum, and Charpy impact energy of 20 J minimum at -20 deg C and 15 J minimum at -40 deg C. Because reported values vary with plate thickness and production batch, the mill certificate should always be used to confirm the actual hardness, tensile, and impact results for the delivered plate. In general, NM600 offers longer wear life than NM500 in abrasive service but with lower ductility and greater fabrication challenges.
Applications in Mining, Construction, and Cement
In the mining industry, NM600 is used for crusher liners, screening plates, and hopper liners, where the plate resists abrasion from ore and rock. In construction machinery, it is applied to bucket edges, side wear plates, and dump truck liners. In cement and quarry plants, NM600 is used for transfer chutes, mill liners, and conveyor liners. Because of its high hardness, the plate withstands intense wear from sand, gravel, and clinker, and its toughness allows it to handle the impact of material falling into hoppers and crushers.
Processing: Cutting, Welding, and Bending
Plasma or laser cutting is recommended for precision processing of NM600 because the material is too hard for conventional shearing at thickness. Welding requires controlled procedures: preheat in the 150-200 deg C range, low-hydrogen electrodes, and controlled interpass temperature, with attention to the carbon equivalent and heat-affected-zone toughness; an approved welding procedure specification should be used for the exact plate thickness and heat. Cold bending is possible for thin plates but not recommended for thick sections; for thick plates, design without forming or use thermal forming. NM600 is not corrosion resistant, so if corrosion is a concern, plan coatings or use overlay protection.
Frequently Asked Questions
What hardness should I expect for NM600? Typical hardness is 570-640 HBW, with a nominal value of 600 HBW; insist on Brinell readings on the mill test certificate.
Is NM600 weldable? Yes, with controlled procedures including preheat, low-hydrogen consumables, and controlled interpass temperature; do not weld without an approved WPS for the exact thickness and heat.
Can NM600 be bent on a press brake? Thin plates may be cold-formed with care, but thick plates should be designed without forming or formed thermally because of the limited ductility of the grade.
Is NM600 better than NM500? NM600 gives longer wear life in abrasive conditions but less ductility and more fabrication challenge; choose based on the abrasion-versus-impact balance of the application.
Does NM600 resist corrosion? No, NM600 is a carbon-martensitic steel and is not corrosion resistant; use coatings or overlays where corrosion is expected.
Which standards apply to NM600? The NM series is governed by GB/T 24186 in China, and Brinell hardness is measured per EN ISO 6506; confirm the applicable edition with the supplier.
Is merchant NM600 suitable for ballistic applications? No. Armor service requires dedicated ballistic certification and specific processing; a standard NM600 plate should not be assumed to be ballistic-rated.
