nonuniform hardening

例句：

1. 1. The steel was nonuniformly hardened during the manufacturing process.
   在制造过程中，钢材是非均匀硬化的。
2. 2. This material exhibits nonuniform hardening characteristics when subjected to high temperatures.
   这种材料在高温下表现出非均匀硬化特性。
3. 3. The researcher found that the nonuniform hardening of the material could be attributed to its composition.
   研究者发现，材料的非均匀硬化可以归因于其成分。