熱作模具鋼和冷作模具鋼的工作條件的主要區別在于熱作模具鋼的工作條件的主要特征是與鐵水接觸。熱作模具主要包括錘鍛模、熱擠壓模和壓鑄模。由于熱作模具鋼工況的特點，會帶來以下問題：

The main difference between the working conditions of hot work die steel and cold work die steel is that the main feature of the working conditions of hot work die steel is contact with molten iron. Hot working die mainly includes hammer forging die, hot extrusion die and die casting die. Due to the working conditions of hot working die steel, the following problems will be brought:

模具型腔表面金屬發生熱疲勞(開裂)。

Thermal fatigue (cracking) of the metal on the surface of the mold cavity.

熱作模具的工作特點是間歇性的。每次形成鐵水時，須用水、油、空氣等介質對型腔表面進行冷卻。因此熱模的工作狀態是反復加熱和冷卻，然后模具型腔的表面金屬經歷反復的熱脹冷縮，即反復的拉壓應力作用。結果，模具型腔表面出現裂紋，稱為熱疲勞現象。

The working characteristics of hot working dies are intermittent. Every time molten iron is formed, the cavity surface must be cooled by water, oil, air and other media. Therefore, the working state of the hot mold is repeatedly heated and cooled, and then the surface metal of the mold cavity undergoes repeated thermal expansion and cold contraction, that is, repeated tensile and compressive stress. As a result, cracks appear on the surface of the mold cavity, which is called thermal fatigue.

因此，提出了熱模具鋼的二個基本性能要求。即，它具有高抗熱疲勞性。一般來說，影響鋼的抗熱疲勞性能的主要因素有：

Therefore, two basic performance requirements of hot die steel are put forward. That is, it has high thermal fatigue resistance. Generally speaking, the main factors affecting the thermal fatigue resistance of steel are:

①鋼的導熱系數。鋼的高導熱性可以降低模具表面金屬的受熱程度，進而降低鋼的熱疲勞傾向。一般認為鋼的熱導率與含碳量有關，含碳量高時熱導率低，因此熱作模具鋼不宜采用高碳鋼。生產中一般采用中碳鋼（C0.3%5～0.6%），含碳量較低。

① Thermal conductivity of steel. The high thermal conductivity of steel can reduce the heating degree of the metal on the die surface, thereby reducing the thermal fatigue tendency of steel. It is generally believed that the thermal conductivity of steel is related to the carbon content. When the carbon content is high, the thermal conductivity is low, so high carbon steel should not be used as hot work die steel. Medium carbon steel (c0.3% 5 ~ 0.6%) is generally used in production, with low carbon content.

會導致鋼材的硬度和強度下降。也是不利的。②鋼材的臨界點影響。一般鋼的臨界點（Acl）較高。鋼的熱疲勞傾向越低。因此。一般通過添加合金元素Cr、W、Si等來提高鋼的臨界點，進而提高鋼的抗熱疲勞性能。

It will reduce the hardness and strength of steel. It is also disadvantageous. ② Critical point effect of steel. Generally, the critical point (ACL) of steel is high. The lower the thermal fatigue tendency of steel. Therefore. Generally, the critical point of steel is improved by adding alloy elements Cr, W, Si, etc., so as to improve the thermal fatigue resistance of steel.

型腔表面的金屬被加熱。

The metal on the surface of the cavity is heated.

一般錘鍛模具工作。模腔表面溫度可達300-400℃以上，熱擠壓模具可達500-800℃以上；壓鑄模腔的溫度與壓鑄材料的種類和澆注溫度有關。例如，壓鑄黑色金屬時，型腔溫度可達1000℃以上。

Generally, hammer forging dies work. The surface temperature of the die cavity can reach more than 300-400 ℃, and the hot extrusion die can reach more than 500-800 ℃; The temperature of die-casting cavity is related to the type of die-casting material and pouring temperature. For example, when casting ferrous metal, the cavity temperature can reach more than 1000 ℃.

山東模具鋼廠家認為如此高的工作溫度會顯著降低型腔表面的硬度和強度，在使用過程中容易出現堆積現象，為此熱作模具鋼的基本應用性能要求是高熱塑性變形抗力，包括高溫硬度和高溫強度，以及高熱塑性變形抗力，這實際上反映了鋼的高回火穩定性。由此可以找到各種熱作模具鋼合金化的方法，即參與Cr、W、Si。和其他合金元素可以提高鋼的回火穩定性。

Shandong die steel manufacturers believe that such a high working temperature will significantly reduce the hardness and strength of the cavity surface, which is prone to accumulation in the process of use. Therefore, the basic application performance requirements of hot work die steel are high thermoplastic deformation resistance, including high temperature hardness and high temperature strength, as well as high thermoplastic deformation resistance, which actually reflects the high tempering stability of the steel. Thus, various methods of alloying hot work die steels can be found, that is, participating in Cr, W, Si. And other alloy elements can improve the tempering stability of steel.

由于熱作模具鋼工況的特點，會帶來以上兩種問題，希望能給夠您好的幫助，當然您對此有疑問，可以隨時關注我們網站http://www.6886774.cn并隨時聯系我們，為您提供新資訊。

Due to the working conditions of hot working die steel, the above two problems will be brought about. I hope I can give you enough help. Of course, if you have any questions about this, you can follow our website at any time http://www.6886774.cn And feel free to contact us to provide you with new information.