高張力 鋼材의 急速入熱後 冷却速度에 따른 組織 및 硬度變化의 硏究 = A study micro structure and hardness change for cooling rate of rapid heated high strength steel

다국어 초록 (Multilingual Abstract)

The weld heat-affected zone of high strength steel was studied and then temperature range is from 1350℃ to 1400℃ Experiment was conducted about high strength steel, SM 58. Their structural and hardening properties were observed by rapid heating and cooling.
The results obtained are as follows:
1) The structure was changed by rapid heating above 1350℃ and cooling.
That is, the anisotropic structure before rapid heating became isotropic structure after cooling.
2) When the cooling temperature range was from 800℃ to 500℃ and cooling rate range was from 1.6℃/sec to 4.3℃/sec, structures changed were similar each other, but except 23℃/sec.
3) The hardness value had Hv from 190 to 230 when the heating temperature was from 800℃ to 500℃ and cooling rate was changed from 1.6℃/sec to 4.3℃/sec, but for 23℃/sec, vickers hardness had the value from 410 to 430.