Samples of three different ferritic steels: conventional AISI410S and two experimental oxide dispersion-strengthened alloys Сr16ODS and EP450ODS, were uniformly ion-doped with helium to concentrations of 0.2 and 1 at% and annealed in vacuum at 1023K. Subsequent TEM studies revealed various patterns of gas porosity development in them: a bimodal distribution of gas bubbles near the grain boundaries in the AISI410S and Сr16ODS alloys and a uniform growth of bubbles within the entire volume of grains in EP450ODS alloy. Measurements of bubbles from different samplings depending on the mode of growth, type of alloy and the doping level showed that the surface area of bubbles does not change during thermal growth of gas porosity, but remains proportional to a concentration of implanted helium, and for all alloys is within the range from $1\times {10}^4$ to $2\times {10}^4{\text{m}}^2\text{/mole}$. Regardless the type of material the coarsening of the bubbles occurs according to the mechanism of migration and coalescence. The volume of gas porosity increases during the growth of bubbles approximately in proportion to their size. It is determined that the gas pressure inside the bubbles is not equal to the surface tension pressure. The dependence of pressure on the bubble size at a constant temperature repeats the isotherm for real gas and is much stronger than previously thought. It is concluded that all the bubbles, regardless of the gas pressure inside, are in a state of thermodynamic equilibrium.

将三种不同的铁素体钢样品：常规的AISI410S和两种实验性的氧化物弥散强化合金Сr16ODS和EP450ODS均匀地掺入氦离子，浓度分别为0.2和1 at％，并在1023 K的真空下退火。随后的TEM研究揭示了其中各种不同的气孔发展模式：AISI410S和Сr16ODS合金中晶界附近气泡的双峰分布，以及EP450ODS合金中整个晶粒中气泡的均匀增长。根据生长方式，合金类型和掺杂水平对来自不同采样的气泡的测量结果表明，气泡的表面积在气体孔隙率热增长期间不会发生变化，而是与注入的氦气浓度成正比，并且对于所有情况合金在以下范围内$\mathrm{1个}\times {10}^4$ 至 $2\times {10}^4{\text{米}}^2\text{/痣}$。无论材料的类型如何，气泡的粗化都是根据迁移和聚结的机理发生的。气泡生长期间，气孔的体积大约与气泡的大小成比例地增加。确定气泡内部的气体压力不等于表面张力压力。在恒定温度下，压力对气泡大小的依赖性重复了真实气体的等温线，并且比以前认为的要强得多。结论是，所有气泡，无论内部的气压如何，都处于热力学平衡状态。