球磨机衬板材料液态模锻及其组织性能研究

发布时间：2018-09-11 21:42

【摘要】：本文针对当前砂型铸造球磨机衬板存在收缩缺陷、组织粗大、使用寿命较短的问题,提出了以液态模锻工艺制造衬板的技术思路,研究了典型衬板材料组织性能特点,并设计了成套液锻衬板技术方案。首先,选取球磨机衬板的两种典型材料中低合金耐磨钢ZG60Cr4MnMoCu和高锰钢改进材料ZGMn1 3Cr2,利用SEM、EDS、XRD、MLD-10B冲击磨料磨损试验机及其他检测设备,研究了液态模锻球磨机衬板材料的组织、耐磨性及其他力学性能的特点,得到了比压对液态模锻球磨机衬板材料组织与性能的影响规律,分析了与砂型、金属型重力铸造相比,液态模锻球磨机衬板的极大优越性。其次,进行了球磨机衬板液态模锻工艺方案设计,得到了成套液锻球磨机衬板工艺,设计了一套专用液锻模具、一台液态模锻机以及液锻球磨机衬板生产所需相关附属设备。最后,利用PROCAST对液锻球磨机衬板工艺进行了数值模拟和虚拟正交试验,利用ANSYS对液锻球磨机衬板模具进行了校核和优化。得到的主要结论如下:(1)液态模锻ZG60Cr4MnMoCu的冲击磨料磨损耐磨性明显优于金属型重力铸造,其磨损速率仅为金属型铸造的74%。液态模锻ZG60Cr4MnMoCu的耐磨性随比压的增大呈非线性规律增加,当比压较低时,随着比压增大,抗磨性显著提高;当比压高于130MPa后,再提高比压,抗磨性提高不明显;(2)液态模锻ZG60Cr4MnMOCu磨损机理为一开始以粘着磨损、磨料磨损为主,然后逐渐发展成只有磨料磨损为主,最后发展成磨料磨损和表面疲劳磨损共同存在、相互促进的过程;(3)铸态时,液态模锻ZGMn13Cr2试样耐磨性比砂型铸造试样提高14.8%,比金属型铸造试样提高15.3%;经热处理后,液态模锻试样耐磨性比砂型铸造试样提高8%,比金属型铸造试样提高14.8%;(4)比压对于改善ZGMn13Cr2晶粒尺寸有显著作用。比压越大,晶粒越细,但是随着比压增大,细化作用将逐渐减弱,当比压增大到228MPa时,继续增大比压将不会继续细化晶粒;(5)比压对于碳化物析出有抑制作用,比压越大,析出碳化物越细越少。比压能够改变析出碳化物类型,当比压增大到140MPa后,M3C碳化物将不再出现,此时只出现M7C3碳化物,主要分布在晶界;(6)球磨机衬板液态模锻的浇注方案为有挡渣功能的翻转包+流槽过滤网+圆形缓冲浇注室,加压方案为主缸加压锁模+下缸和补压缸局部增压补缩,出件方案为下压头带动顶杆快速出件;(7)经过虚拟正交试验得出,球磨机衬板液态模锻生产最优工艺参数为补压压头比压230MPa,充型速度46.167mm/s,浇注温度1500℃,模具预热温度600℃。通过对两种典型的球磨机衬板材料的组织性能研究,证明了用液态模锻工艺制造球磨机衬板在提高其耐磨性和减少凝固缺陷、延长使用寿命方面的巨大优势。同时通过对球磨机衬板的工艺方案设计和数值模拟分析,明确了球磨机衬板液态模锻技术方案是切实可行的,扩大了液态模锻工艺在黑色金属产品的应用范围,对于推广液态模锻在工业生产中的运用起到了一定的积极作用。
[Abstract]:Aiming at the problems of shrinkage defect, coarse structure and short service life of lining plate of sand mold casting ball mill at present, this paper puts forward the technical thought of manufacturing lining plate by liquid forging technology, studies the characteristics of typical lining material and designs a set of technical scheme of liquid forging lining plate. Firstly, two typical lining plates of ball mill are selected. ZG60Cr4MnMoCu and ZGMn1 3Cr2 were used to study the microstructure, wear resistance and other mechanical properties of the lining material of liquid die forging ball mill. The effect of specific pressure on the structure and properties of the lining material of liquid die forging ball mill were obtained by means of SEM, EDS, XRD, MLD-10B impact abrasive wear tester and other testing equipment. Secondly, the design of the lining plate of the ball mill by liquid forging is carried out, and the lining plate technology of the ball mill by liquid forging is obtained. A set of special liquid forging die, a liquid forging machine and the lining of the ball mill by liquid forging are designed. Finally, the numerical simulation and virtual orthogonal test of the lining plate technology of the liquid forging ball mill are carried out by using PROCAST. The lining plate die of the liquid forging ball mill is checked and optimized by using ANSYS. The main conclusions are as follows: (1) The impact abrasive wear resistance of the liquid forging ZG60Cr4MnMoCu is obviously better than that of the metal. The wear rate of mold gravity casting is only 74% of that of metal mold casting. The wear resistance of liquid die forging ZG60Cr4MnMoCu increases nonlinearly with the increase of specific pressure. When the specific pressure is low, the wear resistance increases significantly with the increase of specific pressure; when the specific pressure is higher than 130MPa, the wear resistance of liquid die forging ZG60Cr4MnMOCu increases slightly with the increase of specific pressure. The wear resistance of liquid die forged ZGMn13Cr2 specimens is 14.8% higher than that of sand mold cast specimens and 15.3% higher than that of metal mold cast specimens. After heat treatment, the wear resistance of liquid die forging sample is 8% higher than that of sand casting sample and 14.8% higher than that of metal casting sample. (4) Specific pressure has significant effect on improving the grain size of ZGMn13Cr2. The specific pressure can change the type of carbide precipitated, when the specific pressure increases to 140 MPa, M3C carbide will not appear, at this time only M7C3 carbide, mainly distributed in the grain boundary; (6) ball mill liner liquid die forging pouring square The case is a turning-over package with slag-stopping function, a flow channel filter net and a circular buffer pouring chamber. The pressurization scheme is a main cylinder pressurized die-locking, a lower cylinder and a supplementary cylinder pressurized and fed, and the output scheme is a lower pressure head driven the rapid ejection of the ejector rod. (7) Through the virtual orthogonal test, the optimum technological parameter of the liquid die forging production of the ball mill liner is the specific pressure of the supplementary pressure head 2. 30 MPa, filling speed 46.167 mm/s, pouring temperature 1500 C, mold preheating temperature 600 C. By studying the microstructure and properties of two typical ball mill liner materials, it is proved that the liquid die forging process has great advantages in improving its wear resistance, reducing solidification defects and prolonging its service life. The process scheme design and numerical simulation analysis of the liner show that the liquid forging technology scheme of the liner plate of the ball mill is feasible, and the application range of the liquid forging technology in ferrous metal products is enlarged.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG242;TG316.3

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