HPb59-1黄铜变质细化晶粒组织的热稳定性

Thermal Stability of Modified Grain of Brass HPb59-1

对微量B变质细化的HPb5 9 1黄铜晶粒组织在热加工温度范围保温时晶粒长大情况 ,以及添加微量Zr对它的稳定作用进行了试验研究。结果表明 ,热加工温度下材料内部正常晶粒长大不会使其丧失变质细化效果 ,晶粒仍比无变质细化的铸棒细得多。然而在较长时间或较高温度下材料出现了始于表面、迅速向心部推进的反常晶粒长大 ,晶粒粗化至mm级。微量Zr的加入对变质细化效果和正常晶粒长大速率的影响都不大 ,然而有效地抑制了上述反常晶粒长大。

The thermal stability of refined grain of trace B and an additional trace Zr modified brass HPb59-1 during holding at thermal processing temperature range was examined. The results showed that the normal growth of refined grain at the pertinent thermal processing temperature range and holding time has no deteriorative effect on the refinement, i.e., the refined grain was still much finer than unmodified grain. However, an abnormal rapid growth of the refined grain up to couple of mm from surface toward center of the alloy took place with prolonging holding time or relevant high temperature. Although an additional trace Zr has the slight effect on modification and normal growth rate of refined grain, it can inhibit effectively the above mentioned abnormal grain growth of refined grain.