크로마이트 砂中의 不純物과 燒着과의 關係에 對하여

국문 초록 (Abstract)

大型鑄鋼用 Chromite 砂中의 不純物과 燒着現象과의 關係를 究明하기 위해 不純物 含量이 각각 틀린 3種의實驗用 Core를 製作하여 鑄入함으로써 Core에의 溶鋼浸透狀況을 調査하였다. 또 Table 5에 있는 化學成分으로 試片을 만들어 1000℃ ∼ 1400℃ 溫度범위에서 그의 熱間壓縮强度를 測定했다.
Setting Sand mold等 有機粘結劑를 使用하는 鑄型의 경우에는 그 效果가 현저하다. 이와 같이 燒着(metal penetration)과 Chromite Sands의 Sintering사이에는 重要한 相關性이 있음이 認定되고 있다. 그러나 Chromite Sands도 SiO₂를 中心으로 하는 不純物 含量에 따라 Chromite Sands의 燒結特性이 좌우되고 나아가서는 耐燒着性도 영향을 받게 된다. 따라서 Pouring(鑄入) 試驗을 通해 Chromite Sands의 Penetration mechanism(燒着機構)을 糾明하고 또 Chromite Sands의 耐燒着生을 低下시키는 不純物 含量의 영향을 檢討해 보았다.

다국어 초록 (Multilingual Abstract)

In order to clarify the relationship between the impurities of chromite sands for heavy section steel c astings and metal penetration, 3 kinds of cores with different impurities contentwere prepared and metal penetration into them was investigated.
And that in the range of 1000℃ to 1400 ℃ the hot compressive strength of specimen of the chemical components in Table 5 was measured.
The results obtained are summarized as follows:
1. Two kinds of impurities were contained in chromite sands; One was largely composed of SiO₂, MgO and FeO, and the other largely composed of SiO₂, MgO and Al_(2)O_(3).
2. The more the content of the impurities of chromite sands was, the deeper and severer the metal penetration and sintering, of chromite sands were respectively.
3. In case much impurities are contained in chromite sands, the resistance of chromite sands mold to metal penetration was reduced and metal penetration was liable to occur.
4. Impurity grains over 1200℃ lowered the hot compressive strength of chromite sands.
5. The sintering of chromite sand mold in the range of 1100℃∼1300℃ occurs, not because of the substance among the sand grains, but because of the direct bonding of chromite grains.