网状碳化物

精锻机锻造高碳铬轴承钢时存在网状碳化物不易破碎、锻件合格率低的问题。

While forging the high-carbon chromium bearing steel by the finish forge press , there still remains the issues that the carbide network can not be crushed with the low qualification rate .

结果表明，随铝含量增加，A1温度升高，珠光体相变组织片层间距减小，网状碳化物减少。

The result indicates that temperature A1 goes up as the Al content increases , while lamellar distance in pearlite phase transformation macrostructure decreases and the network carbide decreases .

Ti和C可以直接在液相中反应形成TiC，并可作为渗碳体的结晶核心，使一次渗碳体和共晶渗碳体发生粒化和细化，从而避免连续网状碳化物的形成。

The alloying elements Ti and C can form TiC directly in the melt which acts as nucleus of cementite and causes both primary and eutectic cementite granulated and refined . So the cementite network in this steel can be eliminated .

通过该研究网状碳化物级别达到了2级以下，球化退火时间由原18h减少到了11h。

In this way , the net carbide class can be reduced to 2 , and spheroidizing annealing time decreased from 18 to 11 hours .

在粗大碳化钨颗粒附近能够原位生成先共晶析出相（WC和W2C），在较远处的钢基体中分布着细网状碳化物，同时有（Cr，Fe）7C3等条状复式碳化物生成；

Pre-eutectic phase being WC and W_2C are in-situ separated near to coarse WCp , however , the fine net carbides and long strip carbides ( Cr , Fe ) _7C_3 are formed in the steel matrix far from the WCp .

采用炉前加入1稀土硅铁合金、Ti-Fe、V-Fe、Nb-Fe对铸造多元高合金冷作模具钢进行变质处理，细化了晶粒，使连续网状碳化物断网。

By adopting the 1 # RE-Si-Fe , Ti-Fe , V-Fe , Nb-Fe , the high carbon and high alloy cold - working mould steel is modified . The results show that the carbide of consecutive reticulation is cut and the crystal is diminished .

直径为60mm以下圆钢，通过冷却强度与冷却制度的合理匹配，可以控制心部的冷速达到3℃/s，从而抑制网状碳化物析出。

However , it 's possible to control the cooling rate up to 3 ? ℃ / s so as to suppress efficiently the reticulated carbide precipitation for the round bars ( < 60 ? mm ) by way of matching properly the cooling intensity and cooling rate .

冷辊坯网状碳化物的控制

The Control of the Net Carbide of the Cold Roll Blank

铝元素抑制超高碳钢中网状碳化物析出机理

Mechanism of Network Carbide Precipitation Inhibited by Aluminum in Ultra-High Carbon Steel

以发动机气门座为例，对铁素体冷复压工艺进行了试验研究，分析了网状碳化物的生成条件。

The process of ferrite cold repressing in manufacturing valve seats of engine is investigated .

复合轧辊用高速钢具有高碳和高合金的特征，容易形成大量网状碳化物，这些网状碳化物又硬又脆，会严重降低高速钢的性能，且难以用热处理的方法予以消除。

The high speed steel of composite roll is characteristic of high carbon and high alloy elements .

渗碳后的表层随碳势的不同而有不同的含碳量，高于定比碳一定浓度的碳势不会在表面形成网状碳化物。

The carbon potential which is higher than the balance carbon principle is not easy to come into being network carbide .

在碳含量低于1.7wt%时，添加1.5～2.3wt%的铝，锻造空冷后网状碳化物的析出受到有效的抑制。

With the C content under 1.7wt % , the addition of 1.5-2.3wt % Al restrained the carbide precipitation of forged UHCS effectively .

结果表明，未经稀土变质处理的铸铁组织大部分为粗晶粒奥氏体，还有分布于晶界的网状碳化物；

The results show that the microstructure of the cast iron without being RE modified is mostly coarse-grained austenite and network carbides at the grain boundary .

结果表明，变质可有效地细化高锰钢的铸态组织，消除柱状晶和网状碳化物；

The results show that modifying can effectively fine as-cast structure for high Mn steel , and it can eliminate columnar crystals and networks of carbide .

结果表明，原材料中网状碳化物严重聚集并沿晶析出及基体组织中夹杂物分布不均匀，是造成气门钢性能不合格的主要原因。

It was concluded that main causes of valve steel with unqualified performance were network like precipitation of carbide along grain boundary and uneven distribution of inclusions .

扫描电镜观察表明，加入铝，可抑制锻后空冷条件下先共析网状碳化物的析出；

The microstructure analysis by SEM showed that the precipitation of netlike proeutectoid carbide has been inhibited during air cooling after forging due to Al addition to the UHCs .

指出莱氏体钢铁材料组织中的共晶网状碳化物可以产生塑性变形，而且仍以位错的运动、交割，进而形成亚结构为其变形机制。

The net like carbide in ledeburite structure can bring about the plastic deformation . The deforming mechanism is the movement and inter-action of dislocation and the formation of sub-structure .

因此，减轻磷的偏析、破碎沿晶界连续分布的网状碳化物是提高压铸模综合性能的有效途径。

Thus it is an efficient approach to improve die cast dies ' properties by preventing segregation of phosphorus and breaking the network of carbides distributing along the grain boundaries .

结果表明，对碳含量为1.6%的超高碳钢，添加2%以上的铝，可以显著抑制先共析网状碳化物的析出。

The results show that the precipitation of proeutectoid carbide in net is inhibited remarkably in ultrahigh carbon steel ( UHCs ) containing with in 1.6 % C + 2 % Al .

结果表明，辊身心部较高的内应力和在带状碳化物中存在严重的网状碳化物是造成大型支承辊置裂的主要原因。

The results showed that the higher internal stress and serious carbide network in the banded carbide in the inner roll body were the main causes of heavy back-up roll stationary cracking .

热力学计算与试验均表明：超高碳钢中添加铝使先共析碳化物数量降低是锻造空冷后网状碳化物形成受到有效抑制的根本原因。

Both the thermodynamic calculation and experiments showed that the main reason for inhibition of network carbide of forged UHCS was that the quantity of proeutectoid carbide decreased with the addition of Al .

结果表明，热轧的终轧温度及冷却速度能影响网状碳化物的级别，采用多道次冷轧和球化退火，可使成品钢带获得良好的性能。

The results show that finishing temperature and cooling speed of hot rolling can influence the grade of network carbides . With several courses of cold rolling and spheroidizing annealing , finished steel strips get good properties .

通过采用锻后雾冷+正火雾冷+球化退火的热处理工艺，将轴承钢锻件网状碳化物的合格率从66%提高至93.4%。

By means of the heat treatment process such as mist cooling after forged + normalizing mist cooling + spheroidal annealing , in this case , the qualification rate of carbon network of the bearing steel forging shall be improved from 66 % to ( 93.4 % ) .

轴承钢中碳化物的均匀性对轴承的力学性能及在反复冲击载荷下的寿命有直接影响，当高碳铬轴承钢中存在网状碳化物时，会增加钢的脆性，降低轴承零件的寿命。

The mechanical properties of a bearing and the life under a cyclic impact load are strong influenced by the homogeneity of carbides in bearing steel . When network carbide occurs in high carbon-chromium bearing steel , the steel will become brittle , so that cause the early failure .

网状的碳化物严重影响材料的性能，各项指标都处于最低状态。NET的强大功能。

Net carbide badly affects the material properties and results in every index being the lowest .

WC／钢复合材料中，WC颗粒含量较低的复合材料在高温下溶解严重，基体形成不连续网状复式碳化物沿晶界分布，基体中由于快速冷却析出了许多细小的原位WC颗粒；

In the composites with lower content WC particles , the higher solution of WC particles makes cemented carbide compound along the grain boundary and small in-situ WC particles are found in the matrix .

研究结果表明：（1）变质处理可消除钢中网状共晶碳化物，细化基体组织，还可减轻W、Mo元素偏析；

The result shows that : ( 1 ) the network eutectic carbides were eliminated , matrix structures were refined and the segregation of W and Mo elements were relieved ;

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 .

用REMgTi对低碳铸造高速钢（6W6Mo5Cr4V）模具进行变质处理，消除了钢中网状共晶碳化物，并细化了基体组织，还可减轻W、Mo元素偏析。

Low carbon cast high speed steel ( 6W6Mo5Cr4V ) die was modified using RE-Mg-Ti , network eutectic carbides were eliminated , matrix structures were refined and the segregation of W and Mo elements were relieved .