大型管板类锻件锻造质量的高温模拟实验研究

Investigation and High Temperature Modelling of Heavy Disc Forgings' Quality Control

针对我国目前大型管板等饼类锻件心部夹杂呈片状分布并易在小应力下开裂的质量问题,采用高温物理模拟与云纹法相结合的手段,对锻造控制夹杂物形貌进行了综合实验研究。从制坯工艺入手,经过大量系统的科学实验,分析了经不同制坯工艺、成形工艺锻造后夹杂的形状和尺寸变化,从而得出取消制坯时的镦粗工序,采用直拨制坯、双凸成形的新工艺,获得了优选的制坯工艺拔长比、成形工艺镦粗比的匹配值。本文的研究成果对有效控制夹杂物形貌,使之不成为片状,从而提高大型饼类锻件的内部质量,降低废品率,具有重要意义和实际应用价值。

In the present thesis, the high temperaturh modelling and Moire' method Were used to investigate the interual quality and inclusion shape coutrol in the heavy disc forging process. In heavy disc forging process, the internal inclusion shape is usually a large thin piece,which will initiate crack under some small stress and reduce its mechanical properties. After systematically studying the changes in shape and size of inclusions in the various forging processes, a new technology of direct reduction without first upsetting and 'double side convex'forming process and its optimum technological parameters have been obtained. This technology was first time successfully applied in 1st. Heavy Machinery Plant. It is proved that, this new forging technology has advantages, such as ensure the internal quality, eliminate the first upsetting process, easy to operate, save power, reduce the operating period and production cost. The results of this thesis are important and useful to improve the internal quality and to control the inclusion shape of heavy disc forging and to reduce its reject rate.