双液金属铸焊抛料头的制备与界面研究

Preparation and Interface Study of Two-Liquid Metal Cast Welding Throwing Head

针对立式破碎机抛料头耐磨性不足的问题,从耐磨层材质及制备工艺两方面入手,提出利用双液金属铸焊技术将具有方向性碳化物的过共晶高铬铸铁与低合金钢复合在一起。利用温度场调节方法控制过共晶高铬铸铁碳化物生长方向与受冲击方向垂直,显著细化了原始晶粒,提高了耐磨性,经空淬热处理后,宏观硬度可达HRC 64以上,冲击韧性为4~5 J/cm2。当先浇入型腔的高铬铸铁表面温度下降到700℃时,浇入1 550℃的低合金钢液,得到的复合界面既无严重混料现象,又能达到冶金结合,复合界面两侧元素相互扩散,且最终制备的双液金属铸焊抛料头的成本仅为镶铸硬质合金抛料头的1/3,使用寿命却与之持平。

In order to solve the insufficient wear resistance of the vertical crusher＇s throwing head, the authors combined the hypereutectic high chromium cast iron contAlning directional carbides with the low alloy steel by the two-liquid metal cast welding technology, focusing on two aspects such as the wear-resistant layer material and the preparation process. The growth direction of carbides in the hypereutectic high chromium cast iron is perpendicular to the impact direction by use of the temperature control. The original large grAln microstructure of the cast iron obviously becomes fine and the wear resistance is improved. The macrohardness can reach HRC 64, and the impact toughness is 4-5 J/cm^2 after heat treatment by Alr quenching. During the preparation process of the throwing head, when the surface temperature of the high chromium cast iron was cooled to 700℃, the low-alloy liquid steel was poured at 1 550℃. The obtAlned composite interface of the throwing head shows no serious blending of these two materials, and the diffusion of elements on both sides of the composite interface is uniform. The production cost of the two＇liquid metal cast welding throwing head is only 1/3 of the throwing head cast with the inserted cemented carbide, while the service lives of the two kinds of the throwing heads are kept almost the same.