High-Temperature Resistant Wear-Resistant Steel Plate.As the name suggests, it is a wear-resistant steel plate capable of withstanding high temperatures. As a premium grade wear plate, it features excellent impact toughness.
- "NM" stands for wear resistance;
- "450" refers to its Brinell hardness value;
- "HiTemp" denotes high-temperature resistance.
NM450HiTemp integrates outstanding strength, hardness, toughness and high-temperature resistance in one material, delivering cost-effective wear-resistant solutions for service temperatures ranging from 300°C to 500°C.
Conventional wear-resistant steels are temperature-sensitive; their hardness drops significantly above 200°C. In contrast, this high-temperature wear plate retains its hardness even at temperatures up to 500°C.
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Why Does Temperature Affect the Properties of Wear-Resistant Steel?
Most wear-resistant steels are developed for ambient temperature service conditions. When operating temperature rises, the internal microstructure of the steel plate softens, which results in：
- Reduced tensile strength
- Lower yield strength
- Decreased hardness
- Deteriorated wear resistance
- Shorter service life
High-temperature stability is equally critical as wear resistance for equipment in the following industries：
- Cement clinker conveying systems
- High-temperature slag handling equipment
- Sintering plant machinery
- Coke conveying systems
- Metallurgical material chutes
- Ash conveying equipment for thermal power plants
Accordingly, focusing solely on hardness cannot meet practical service requirements under high-temperature environments.
NM450 VS NM450HiTemp：Basic attribute difference
NM450: A conventional high-strength wear-resistant steel plate. The designation "NM" stands for "wear-resistant", and "450" indicates an average Brinell hardness of approximately 450 HBW. It complies with the national standard GB/T 24186-2022 and is a widely used wear-resistant material in the industrial field.
NM450HiTemp: An upgraded high-temperature resistant wear-resistant steel plate developed on the basis of ordinary NM450. The suffix "HiTemp" clearly marks its high-temperature resistance characteristic, and it is specially designed for wear conditions at 300-500℃.
Key Properties of NM450HiTemp：
| NM450HiTemp | Tensile Strength Rm, MPa | Elongation, % | Brinell Hardness HBW |
|---|---|---|---|
| Required Value | ≥1300 | ≥8 | ≥420 |
| Typical Value | 1594 | 16 | 486 |
Why Does NM450HiTemp Deliver Superior High-Temperature Performance?
Improved Tempering Stability
After continuous soaking at 450°C for 48 hours, the Brinell hardness of standard NM450 decreases by 28%~35%. In contrast, NM450HiTemp only suffers an 8%~10% hardness drop, preventing irreversible material softness during long-term cyclic operation at 300~500°C.
More Stable Tempered Martensite Microstructure
Additional molybdenum and nickel alloying elements are incorporated to suppress carbide coarsening under high temperatures. After 1000 hours of cyclic thermal and mechanical loading, no brittle phases precipitate, eliminating premature cracking and failure of high-temperature slag hopper liners and cladding chute plates.
Markedly Improved Hardness Retention
At a continuous service temperature of 400°C, NM450HiTemp retains over 90% of its room-temperature Brinell hardness (420–460 HBW). In comparison, conventional NM450 retains only 60–65% of its original hardness under the same conditions, leading to a wear rate 2–3 times higher.
Superior Resistance to High-Temperature Softening
This grade allows continuous long-term service up to 500°C, while standard NM450 has a long-term service temperature cap of only 200°C. Taking asphalt mixing heating drum liners as an application example, switching to NM450HiTemp extends liner service life from 4 months to 18~22 months.
Enhanced High-Temperature Oxidation Resistance
Chromium content is raised to 1.4%~1.8%, forming a dense anti-oxidation protective film above 350°C. When applied to sulfur-containing hot cement clinker conveying equipment, it reduces oxide layer spalling and cuts monthly maintenance downtime by more than 40%.
Wear-resistant steel plates and their processed parts
NM450HiTemp VS NM450：Temperature Resistance Range Comparison
NM450: The applicable ambient temperature is generally ≤200°C. Beyond this temperature, its matrix microstructure becomes unstable, resulting in obvious hardness reduction and sharp decline in wear resistance.
NM450HiTemp: Engineered for high-temperature service conditions of 300–500°C. It maintains high hardness (≥420HBW) within this temperature range, eliminating softening failure of conventional wear-resistant steels at elevated temperatures.
Comparison of tensile strength at different temperatures：
Tensile Strength After 48h Soaking at Different Temperatures：
NM450HiTemp Service Applications：
NM450HiTemp is mainly applied to sand & stone heating drums and recycled material heating cylinders. NM400 and Q355B are currently adopted for blade manufacturing; NM450HiTemp is recommended as an upgraded alternative.
Engineering Application Recommendations
Based on the above comparative analysis, material selection suggestions for the two grades are listed as follows：
Scenarios for Selecting NM450：
- Normal or low-temperature wear working conditions with operating temperatures below 200°C;
- General wear-resistant components with tight cost budgets and no high-temperature service requirements;
- Wear-resistant parts operating in extremely cold environments (e.g., NM450E series, suitable for service down to -40°C).
Scenarios for Selecting NM450HiTemp ：
- High-temperature wear working conditions with operating temperatures ranging from 300°C to 500°C;
- High-temperature anti-wear parts such as blades for aggregate heating drums and recycled material heating cylinders;
- High-temperature abrasion environments including metallurgical blast furnace liners, sintering equipment components, and coke oven fittings;
- Applications requiring lightweight equipment and extended service life, as a replacement for composite structures of carbon steel base plates plus ceramic liners.
Why Does NM450HiTemp Deliver Superior High-Temperature Performance?
NM450HiTemp maintains high strength under high-temperature environments mainly thanks to its specialized alloy design and heat treatment process.
Compared with standard NM450, it boasts the following advantages：
- Higher tempering stability.
- More stable metallographic microstructure.
- Better hardness retention capacity.
- Stronger resistance to thermal softening.
- Superior oxidation resistance.
As a result, the steel plate retains excellent wear resistance and load-bearing capacity even under sustained high-temperature conditions.
Contact us now for the latest price quote on the NM450 HiTemp.
FAQ：
What is NM450 steel?
NM450 is a high-strength, wear-resistant steel grade defined under the Chinese GB/T 24186 standard. It is specifically engineered for applications requiring exceptional abrasion resistance, making it ideal for heavy-duty machinery in industries like mining, construction, quarrying, and material handling.
What is NM400 steel?
NM400: A Chinese-standard wear-resistant steel (NM stands for "Nai Mo," meaning wear-resistant in Chinese), NM400 typically has a Brinell hardness (HBW) of 360–440. It's known for its balance of hardness, toughness, and cost-effectiveness, making it popular in Asia and beyond.
What is the difference between Hardox 450 and NM450?
Impact Toughness: Hardox 450 is known for its superior impact toughness, which allows it to absorb energy without fracturing under impact loads. NM450 may exhibit good impact toughness as well, but the exact values may vary depending on the manufacturer and specific heat treatment applied.
What is NM450 equivalent to?
NM450 is equivalent to international grades such as Hardox 450 (Sweden, SSAB), AR450 (ASTM standards), JFE-EH450 (Japan), and Dillidur 450V (Germany).
