Stal narzędziowa H13 kontra A2: kompleksowe porównanie

Szacowany czas czytania: 7 minut

H13 vs A2 tool steel: What is the difference between H13 I A2 steel? In modern manufacturing, tool steel is an indispensable core material as a specialized, high-quality steel. Tool steel maintains its cutting and forming capabilities at extreme temperatures after quenching and tempering. When our customers select materials for complex operating conditions, we typically recommend evaluating them across three core dimensions, which constitute the three critical factors of tool steel performance: wear resistance, toughness, and hot hardness.

Within the AISI (American Iron and Steel Institute) standard system, H13 and A2 are two highly representative foundational steel grades, yet their application scenarios are entirely distinct. H13 (1.2344), as a stal narzędziowa do obróbki na gorąco, is primarily used in high-temperature environments. It exhibits outstanding resistance to thermal fatigue and is widely employed in die-casting molds. Conversely, A2 is an air-hardening stal narzędziowa do obróbki na zimno, designed for conditions at room temperature.

Defining the Operational Environment: Hot Work vs. Cold Work

In selecting tool and die steels, H13 and A2 are often used as typical reference points. The most fundamental difference between H13 and A2 lies in their operating temperatures. H13 maintains its strength at high temperatures, withstanding instantaneous temperatures up to 700°C (1300°F). Of course, H13 also has a temperature limit. Beyond 650°C (1138°F), the strength of H13 material begins to decline. To extend the material’s service life, it is recommended to use higher-purity ESR (Electroslag Remelting) H13 material. A2, on the other hand, is only suitable for ambient temperature environments, with typical operating temperatures below 200°C (400-500°F).

Composition and Mechanical Property Comparison

In the world of tool steels, no single material is perfect. Material selection is fundamentally a trade-off between three core properties: wear resistance, toughness, and hot hardness.

• Toughness. On a toughness rating scale of 1-9 (lowest to highest), H13 rates 9 while A2 rates 5. If your tooling must withstand severe impacts or operate under complex stresses, toughness is the primary consideration. H13 has a lower carbon content and typically achieves a hardness of 40-50 HRC. The low carbon content minimizes the formation of unsolved carbides, thereby enhancing H13’s impact resistance. In contrast, A2 exhibits moderate toughness. To meet hardness requirements in cold-working applications, A2 increases its carbon and carbide content, boosting its hardness but partially reducing its toughness.
• Wear Resistance. On a wear resistance rating scale of 1-9 (lowest to highest), H13 is rated 3, while A2 is rated 6. Wear resistance typically correlates directly with carbon content and the quantity of hard carbide particles in the steel. A2 contains higher carbon. This high carbon content forms abundant hard carbides, giving it significantly superior room-temperature wear resistance compared to H13. Due to its lower carbon content, H13 lacks sufficiently large primary carbide particles to resist abrasive wear. While its vanadium content provides some assistance, it cannot compete with cold-worked steel in a pure wear resistance comparison.
• Red hardness. On the red hardness rating scale of 1-9 (lowest to highest), H13 is rated 6, and A2 is rated 5. While ordinary steel rapidly softens and deforms above 500–550°C, H13 maintains high hardness and strength even at elevated temperatures. A2 lacks the alloying elements necessary to resist high-temperature softening, limiting its application to cold-working environments.

Heat Treatment and Manufacturing Characteristics

Material selection is only the first step; the ultimate performance of tools and dies is often determined by the heat treatment process. Both H13 and A2 are air-hardening, deep-hardening steels that harden by air cooling. Compared to oil or water quenching, air hardening induces minimal thermal stress and poses the lowest risk of deformation. According to some data sources, H13 and A2 exhibit extremely minimal dimensional expansion after proper heat treatment, approximately 0.001 mm/mm.

During tempering, the processes for H13 and A2 steel differ significantly. H13 is a secondary hardening steel, and it is recommended to perform at least two tempering cycles, or even triple tempering. Multiple tempering cycles not only relieve residual stresses but also promote carbide precipitation, resulting in exceptional red hardness and thermal fatigue resistance. A2 steel exhibits a secondary hardening peak around 510°C. However, in cold-working applications, high-temperature resistance is typically unnecessary; instead, sufficient hardness and wear resistance are required. In practice, to achieve high hardness in A2 steel, a lower tempering temperature of 230°C is commonly employed. High-temperature tempering is considered only when extremely high toughness is required or to eliminate retained austenit.

In terms of machinability, with 1% carbon tool steel set as the 100-point benchmark, H13 in the wyżarzany state has a machinability score of approximately 70 points. Similarly, the A2 score in the annealed state is about 60 points. Machining accounts for a significant portion of tool-and-die manufacturing costs. Therefore, machinability is a critical factor that cannot be overlooked.

Aplikacje

• H13 Zastosowania stali narzędziowej:Szeroko stosowana do ogólnych zastosowań w obróbce na gorąco, matryc do odlewów ciśnieniowych (do aluminium, cynku i magnezu), form wtryskowych do tworzyw sztucznych oraz narzędzi do kucia. Nadaje się na matryce do wytłaczania na gorąco do aluminium, magnezu, stali, miedzi i mosiądzu. Stosowana również na stemple, przebijaki i trzpienie do obróbki na gorąco. Może być stosowana jako stal na formy do wnęk obrabianych mechanicznie i jest zalecana do form z tworzyw sztucznych o wysokim stopniu polerowania po rafinacji elektrorezystancyjnej (ESR), a czasami stosowana do silnie naprężonych elementów konstrukcyjnych w przemyśle lotniczym ze względu na odporność na mięknięcie w wysokich temperaturach i umiarkowaną wytrzymałość.
• A2 Tool Steel: A general-purpose air-hardening tool steel with a wide range of tooling applications. Commonly used for blanking and piercing dies in mass production. Also used for cold-forming dies, coining dies, drawing and lamination dies, thread-rolling dies, shear and slitter blades, and forming rolls. It’s a good choice for intermediate-service cold-work tools and dies. It can be used for small molds and inserts, and is preferred for large dies due to low distortion during obróbka cieplna. Sometimes used as an alternative to hot-work steels for hot shearing tools and dies used in the hot extrusion of zinc.

Podsumowanie porównania

In essence, H13 is engineered for severe high-temperature environments, prioritizing hot hardness and strong impact resistance, whereas A2 is a versatile cold-work steel that excels in wear resistance and dimensional stability for room-temperature operations. If you are having trouble deciding between these two materials, please get in touch with us for professional advice.

Powiązane linki

• Przewodnik po obróbce cieplnej stali H13
• Zrozumienie stali narzędziowej hartowanej w powietrzu (takiej jak H13)
• Opanowanie właściwości stali narzędziowej A2: skład, obróbka cieplna i wszechstronne zastosowania
• Równoważne gatunki i porównania stali H13: 1.2344, 1.2343, A2, 4140 i S7
• Stal A2 i obróbka cieplna: kompletny przewodnik