Unfortunately, though flat tappets from China are cheap, their metallurgy is suspect-and the same goes for the quality of their machining, heat treatment and surface-hardening.

不幸的是尽管中国制造的平头挺杆物美价廉，但是其冶金技术遭到质疑，加工、热处理、表面硬化质量也遭质疑。

youdao

The grinding strengthen technology is a new process engineering of surface heat-treatment, which uses a mass of grind heat produced in grinding process to handle workpiece materials.

磨削强化技术是利用磨削加工过程中产生的大量磨削热对工件材料进行表面热处理的新工艺技术。

youdao

Meanwhile, high surface hardness after heat treatment, the coating surface formed into the amorphous and crystalline mixture, the hardness is up to 1200hv.

同时表面硬度高，经热处理后，其镀层表面形成非晶态和晶态的混合物时，硬度可达1200 HV。

youdao

The closest thing out there to LED photomodulation is a controversial procedure called nonablative laser treatment, which uses heat to burn away sub-surface skin so that new cells will replace it.

FORBES: Magazine Article