tempering

/ˈtempərɪŋ/ 28
improve the hardness and elasticity of (steel or other metal) by reheating and then cooling it. "the way a smith would temper a sword"

noun [具体名词][机]回火

But tempering alone is usually not enough.
但是单纯的退火是不够的。

verb [vt. 及物动词]调和(temper 的 ing 形式)

For flat glass, heat tempering is most often used.
对于平板玻璃,热退火是最常用的。

单词造句: