轧制工艺对热轧钨板材组织和性能的影响

比较了一火一道，一火两道和一火三道的热轧工艺制度对钨板材质量的影响，结果表明：采用传统的一火一道工艺轧制的板材无开裂，工艺可靠，但板材纤维组织粗大，有部分再结晶组织出现，切削和磨削过程中出现掉渣现象；采用一火两道工艺轧制时，通过减少两道次轧制之间的时间，可以充分保证板材轧制温度和塑性，轧制的板材中纤维组织细小均匀，保留部分亚晶粒组织。通过适当延长板材最终退火时间可提高后续加工性能；采用一火三道次轧制时，板材加工温度明显降低，加工后出现明显的边裂，加工性能明显降低。因此，可以采用一火两道次工艺轧制磨光钨板材，从而实现加工工艺的优化。

Effects of the Rolling Pass on the Microstructure and Characteristics of Hot Rolled Tungsten Plates

Experiments with one pass per heat, two passes per heat and three passes per heat in the rolling process were designed and carried out in order to improve the microstructure and characteristics of the hot rolled tungsten plates, and also to shorten the production cycle and achieve energy saving. Results of the experiments including the microstructure patterns and it＇s machined characters in linear cut and grinding process for the hot rolled plate were compared respectively, it showed as follows： （a） Although it is a traditional or common rolling technique, in which the tungsten plate was rolled with one pass per heat, the coarse fiber structures with recrystallized crystals was appeared, and will produce off ribs when it＇s machined. （b） When the tungsten plate was rolled with two pass per heat, which is a new technique, the fine fiber structures keeping with part of subgrains obtained, and also to get ideal machined properties of the plate, prolonging annealing time is proved to be very reliable in production practice. （ c ） Although it can achieve finer fiber structures when the tungsten plate was rolled with three pass per heat, results showed that the plate can be easily cracked and became brittle with deteriorated machined properties because of the prolonged rolling process. So we can see that the varied rolling pass have great impact on the microstrncture and characteristics of tungsten plate, and process with two pass per heat can achieve both quality and efficiency, and prove to be the most desirable choices by comprehensive comparison.