三乙胺法冷芯盒制芯工艺的应用

介绍了三乙胺法冷芯盒制芯工艺的热力学、动力学特点,详细阐述了采用该工艺易出现的缺陷及防止措施,总结认为:(1)要严格控制生产环境温度、湿度、原砂的粒度、含水量,同时调整后续的上浸涂、烘干、熔炼工艺参数,使之与射芯砂芯的工艺特性相适应;(2)通过调整排气塞位置而无法解决射砂不全时,需调整射芯嘴位置或增加射砂嘴;(3)通过调整吹胺量来降低砂芯脱盒时的初始强度,增大砂芯二次硬化时强度的提升比例,可以提高砂芯的整体韧性;(4)铸件的N2气孔缺陷可以通过控制铁液的w(N)量、Mn/S比、以及调整树脂中组分Ⅱ的加入量消除。通过采用三乙胺法冷芯盒工艺,壳体类铸件的生产效率提升3倍,综合废品率由原来的10%降低至5%以内。

Application of Triethylamine Cold-Box Core-Making Process

The thermodynamic and dynamic characteristics of the triethylamine cold-box core making process were introduced and the common defects of this process and their prevention measures were described in details. The followings were concluded： （1）It＇s necessary to strictly control the environment temperature,moisture of the production site,grain size distribution and moisture of the raw sand,and as well as,to adjust the parameters of following immersion-coating,drying and iron melting processes to make them suitable to the process characteristics of the core sand to be shot. （2）When the sand core-box couldn＇t be fully filled by sand-shooting and the problem couldn＇t be solved by adjusting locations of venting plugs,it＇s necessary to adjust the locations of the shooting nozzles or increase the shooting nozzle number. （3）By adjusting amount of amine-blowing to enhance the strength increasing ratio during secondary hardening of the core,the toughness of the whole core could be improved. （4） Nitrogen blowholes defect could be eliminated by controlling nitrogen content, Mn/S content ratio and adjusting addition amount of resin-component II. As the result of using triethylamine cold-box process, the productivity of the shell-type castings was increased three times,the general rejection rate was decreased from original 10% to less than 5%.