二次碳化物

WC原始颗粒以各种复式碳化物的形式析出，分别形成枝状或鱼骨状共晶碳化物、网状二次碳化物及大块状碳化物。

Multiple carbides are precipitated from WC particles , which form many different shapes such as dendrite or fishbone eutectic carbide , reticulation secondary carbide and conglomeration carbide .

高CoNi合金钢中二次碳化物的析出与转化

Precipitation and transformation of the second carbides in isothermal tempered high CONI alloy steel

添加Mo和V的高铬铸铁在亚临界热处理时除了二次碳化物（Fe，Cr）23C6的析出外，还有Mo2C和VCr2C2碳化物析出，有效地提高了合金抗磨料磨损能力。

During sub-critical treatment , the high chromium cast iron containing molybdenum and vanadium precipitates secondary carbides of Mo_2C and VCr_2C_2 besides ( Fe , Cr ) _ ( 23 ) C_6 , which improves the abrasion resistance effectively .

铸件合金层厚度均匀，基体组织为树枝状的奥氏体，增强相为二次碳化物（Cr，Fe）7C3和渗碳体型碳化物Fe3W3C。

Casting composite layer is even and firm , the matrix structure of composition is dendroid austenite , and the reinforced phase is secondary carbide ( Cr , Fe ) 7C 3 and cementite-like carbide Fe 3W 3C .

在900℃疲劳试验过程中，DZ40M合金中初生碳化物M7C3和MC发生溶解，同时，沉淀析出大量细小的二次碳化物M23C6，它与基体具有立方取向关系。

The results show that primary carbides M 7C 3 and MC are dissolved and secondary carbide M 23 C 6 is precipitated profusely , which is assumed to be a cube cube orientation relationship with the matrix .

使用3.5a（年）后二次碳化物增多，共晶碳化物附近的无析出区消失，并在许多共晶碳化物内部形成黑斑组织。

After the steel had been serviced for 3.5 years , the precipitate free zone ( PFZ ) near by eutectic carbides has disappeared and black speckle microstructure formed in eutectic carbide .

二次碳化物对马氏体钢三体磨料磨损性能的影响

Effect of secondary carbide on the three-body abrasive wear resistance of martensitic steel

二次碳化物对基体三体磨粒磨损特性的影响

The Effects of Secondary Carbide on The Character of Matrix Under Three-Body Abrasion

碳量2.63%为奥氏体能否析出二次碳化物的临界值。

2.63 % C is the critical value whether the austenite precipitates secondary carbides .

退火过程中析出的二次碳化物阻碍再结晶晶界的迁移，从而影响再结晶层的界面推移速率。

The secondary carbides have a strong influence on recrystallization rate by retarding the migration of recrystallization grain boundaries .

选用三种不同碳、铬含量的耐磨钢，通过热处理获得不同数量的二次碳化物和马氏体基体。

Based on the two-film theory of mass transfer , the dynamics character of carbon dioxide absorption in second carbonation was studied .

当二次碳化物未析出时，碳量的增加使奥氏体稳定性增加，而一旦二次碳化物析出，碳量的增加使奥氏体的稳定性变差；

The increase of carbon content leads to primary austenite more stable when no secondary carbides precipitating , however , once secondary carbides precipitate , it results in the instability of primary austenite .

钢中的共晶碳化物、δ&铁素体、服役过程中析出的二次碳化物和σ相以及过量的硅和硫含量都促进早期热疲劳开裂。

The shrinkage porosity is a primary factor influencing the early ther - mal fatigue failure . Eutectic carbides ,δ - ferrites in the steels , secondry carbides ,σ phases precipitating in work , and excessive sF and S contents promote it .

铬锰铜合金白口铸铁磨球材料，经930～1050℃正火处理，具有共晶碳化物＋珠光体＋弥散二次碳化物的微观结构，能适应煤磨机中磨料磨损和磨蚀磨损的实际工况条件。

The microstructure of Cr Mn Cu white cast iron grinding ball is ledeburite + pearlite + dissipate secondary cementite after 930 ~ 1050 ℃ normalising . The material can be fit for the environment of grinding wear and corrosion wear in grinding coal machine .

实验结果表明：1.淬火温度、回火温度、疲劳裂纹扩展机制、二次碳化物的尺寸、试样的淬硬深度等因素均影响疲劳裂纹扩展速率。

It is showed that : 1 . The quenching temperature , or the tempering temperature , or thc mechanism of crack propagation , or the size of carbide particals , or the depth of hardening effects to the rate of crack propagation da / dN .

因此，为保证回火时有足够的M2C型二次硬化碳化物析出，最佳淬火温度为1050～1100℃，保温时间为30～60min。

Therefore , in order to ensure an effective precipitation of the M 2C type secondary hardening carbides during tempering , the optimum quenching temperature for the current steel is about 1050 ~ 1100 ℃, with holding time of 30 ~ 60min .

TEM观察表明：二次正火使碳化物颗粒变细，且改善了碳化物沿晶界的分布状态。

TEM examination shows that the second normalizing fines the grains of carbide and improves the state of distribution of carbides by grain boundaries .