Under certain conditions, it is reasonable to directly process products with rolled profiles. In spite of this, the tool steel that needs to be forged still accounts for a considerable proportion in the manufacturing plant. In addition to hot forging can reduce machining and make full use of steel and other reasons, tool steel forging is conducive to improve the internal quality of steel, the role of the following aspects.

1)—般说来，钢材的截面愈小，锻造比愈大，冶金质量本身就愈好。出此凡是需要先经过改缎再坦行加上的工具毛坯，席尽可能选用较小截面的钢材改锻为较大截向的毛坯，这样有利于保证工具钢内部有较好的冶金质量。

1) Generally speaking, the smaller the section of steel and the larger the forging ratio, the better the metallurgical quality itself. Therefore, for the tool blank that needs to be changed to Satin first and then to smooth, the steel with smaller cross section should be used instead of forging the blank with larger cross section as far as possible, which is conducive to ensuring the better metallurgical quality of the tool steel.

2)改锻使工具钢内部的流线分布比较合理。例如盘形铣刀如果用略大于具外径的钢材落料后直接进行机械加工，从钢材利用率和降低加工成本方面考虑是合理的，然而钢内央杂物排列的方向、碳化物偏析的排列方向都和切削刃口平行，即处于大的受力方向，对使用性能不利c如果用小规格的俐材经过改锻

2) The distribution of streamline in tool steel is more reasonable by changing forging. For example, if the disk milling cutter is machined directly after blanking with steel slightly larger than the outer diameter, it is reasonable to consider the utilization rate of steel and reduce the processing cost. However, the arrangement direction of impurities in the steel center and carbide segregation are parallel to the cutting edge, that is, in the direction of large force, which is unfavorable to the service performance

(镦粗后打扁)，则流线呈放射状(径向)分布，改善了铣刀的性能.

The flow line is radially distributed, which improves the performance of milling cutter

3)通过改锻商可能改善关键部位的材质，使上具受力严重的部他的材质获得改 善，从而收到大幅度提高工具钢寿命的效果。

3) It is possible for the forger to improve the material of the key parts, so as to improve the material of the parts with severe stress, so as to greatly increase the service life of the tool steel.

4)锻造的加热过程想着扩散退火的作用。工具钢改锻时的加热温度可以略高于钢锭开坏的加热温度，因为在开坯和轧制之后，品内和品问偏析己明显改 善。钢材改银加热时局部熔化的倾向减小。加热温度愈高，保温时刘愈长，偏析酌作用愈显著。显然模具钢在高温加热的过程市奥氏体晶粒长大，似在高温加

4) The heating process of forging is affected by diffusion annealing. The heating temperature of the tool steel can be slightly higher than that of the ingot when the forging is changed, because the segregation in and between products has been improved obviously after the bloom and rolling. When the steel is changed to silver, the tendency of local melting decreases. The higher the heating temperature is, the longer the holding time is, and the more significant the effect of eliminating segregation is. Obviously, the austenite grains of die steel grow up in the process of high temperature heating

热后紧接着进行压力加工，则可以细化英氏体晶粒，如果终锻温度控制得好、锻后冷却方式合理，则可以抑 制网状碳化物的出现，达对于保证钢的RJ加工性和使用件能都十分重要，因此工具钢的终锻温度贩予以控制，一般应控制在表3．2的范围内。

If the final forging temperature is well controlled and the cooling mode after forging is reasonable, the occurrence of network carbide can be restrained, which is very important to ensure the RJ machinability of steel and the performance of parts used. Therefore, the final forging temperature of tool steel should be controlled within the range of table 3.2.