NM360 is a high-strength wear-resistant steel plate. Its designation follows the material nomenclature system in the European standard EN 10297-2:2023 "Seamless Circular Steel Tubes for Mechanical and Automotive Engineering – Part 2: Cold Drawn Tubes of Alloy and Non-Alloy Steels", but it is more broadly categorized under wear-resistant steel standards such as EN 13242:2022 "Aggregates for Unbound and Hydraulically Bound Mixtures for Construction Works – Specifications" and industry-wide specifications. It should be noted that comprehensive technical specifications for the "NM" series of wear-resistant steels are often supplemented by national or corporate standards, such as China's GB/T 24186-2019 "High-Strength Wear-Resistant Steel Plates for Construction Machinery". As a medium-to-high hardness grade within the wear-resistant steel family, NM360 is widely used in various high-wear applications due to its excellent wear resistance and balanced overall performance.
The designation "NM360" has the following meaning:
"NM" is an abbreviation for "Nai Mo ", which means wear-resistant. In international context, "NM" has become a code for high-strength wear-resistant steels, distinguishing them from ordinary structural steels.
"360" indicates the average Brinell hardness (HBW) of the steel after quenching and tempering heat treatment is 360. According to EN ISO 6506-1, its typical hardness range is 330–390 HBW. This hardness level represents a medium-to-high wear-resistance grade, significantly higher than that of ordinary structural steels (e.g., ~150 HBW for S355), yet lower than higher-hardness grades like NM400, NM450, and NM500. It achieves an excellent balance between wear resistance, machinability, and toughness.
The primary application of NM360 steel plate is in manufacturing components operating in high-wear and high-impact environments, especially where resistance to abrasive, impact, and cutting wear is required. Typical applications include:
Construction Machinery: Bucket teeth, side cutters, cutting edges, base plates, and wear liners for excavators and loaders.
Mining and Quarry Equipment: Liners for crushers, screens, feeders, mine car bodies, chutes, and hoppers, resisting severe abrasion from ores and rocks.
Dump Trucks and Transport Equipment: Floor, side, and tailgate panels for dump truck bodies, extending service life when transporting abrasive materials like sand, gravel, ore powder, and coal.
Agricultural Machinery: Plowshares, harvester blades, conveyor chain plates, and other components prone to wear.
Cement and Power Industries: Mill liners, fan blades, coal conveyance pipelines, and dust collection equipment components subjected to erosive particle flow.
Its main characteristics include:
High Hardness and Excellent Wear Resistance: A surface hardness of 360 HBW effectively resists abrasive wear, providing a service life far exceeding that of ordinary steels.
Good Toughness and Impact Resistance: Through quenching and tempering, the material maintains sufficient toughness while achieving high hardness, enabling it to withstand moderate impact loads without cracking or spalling.
Weldability: With proper preheating and welding procedures (e.g., using low-hydrogen electrodes), NM360 offers acceptable weldability, facilitating on-site repairs and component assembly.
Good Cold Formability: Despite its high hardness, NM360 can undergo limited cold bending at room temperature, meeting the requirements for manufacturing complex parts.
High Cost-Effectiveness: Compared to higher-hardness grades, NM360 offers better value by ensuring adequate wear life at a more competitive price, delivering superior overall cost-performance.
Ultrasonic Testing (UT)
A key non-destructive testing technique that uses high-frequency sound waves to detect internal flaws in steel plates. The probe emits sound waves, which reflect when encountering defects such as cracks or inclusions. The receiver captures the echoes, enabling precise determination of defect location and size. With high sensitivity, strong penetration, and fast inspection speed, UT effectively ensures internal quality, widely used in the production of heavy plates, pressure vessel plates, and other high-end products to guarantee safety and reliability.
Magnetic Particle Testing (MT)
A common surface inspection method that magnetizes the workpiece, causing leakage magnetic fields at surface or near-surface defects like cracks or inclusions, which attract magnetic particles to form visible indications. Simple to operate and highly sensitive, MT is suitable for rapid inspection of surface and near-surface flaws in ferromagnetic materials, widely used for online or offline inspection of plate edges, ends, and welds, ensuring product quality and safety.
Penetrant Testing (PT)
A non-destructive method for detecting surface-breaking flaws. A penetrant liquid is applied to the cleaned steel surface, allowing it to seep into defects such as cracks or pores. After removing excess penetrant, a developer is applied, causing the trapped penetrant to bleed out and form visible indications. Simple and cost-effective, PT is suitable for inspecting surface defects in various non-porous materials, commonly used for welds, castings, and complex components, effectively ensuring surface quality of steel plates.
