連鑄熱作模具鋼H13的技術開發

Development of Continuous Cast H13 Hot-die Steel

陳志遠(C. Y. Chen) ； 張顧齡(K. L. Chang) ； 吳政彥(C. Y. Wu) ； 陳郁仁(Y. J. Chen)

《鑛冶：中國鑛冶工程學會會刊》 60卷3期 (2016/09) Pp. 107-114

https://doi.org/10.30069/MM.201609_60(3).0008

摘要

H13熱作模具鋼因連鑄技術難度高而難以穩定連鑄，本研究分析中龍電爐廠設備與生產特性，據以規劃試驗及生產配套措施。本研究應快速造渣精煉脫硫技術，藉由快速渣相分析方法可獲得礦物相的組成和分佈，提供造渣適化路徑與投料模式以便即時調整渣性，避免因高合金添加量導致過於籠長的精煉時程導致後續復[P],[S]問題。開發連鑄歷程鑄胚溫度模擬技術，分析H13澆鑄溫降履歷幫助精準掌握最適製程參數，使鑄胚溫度穩定避開鋼胚脆性區，改善H13連鑄時常見的鋼胚撕裂與斷胚問題，最終順利產製合格H13連鑄胚。歷經多次現場試製，穩定掌握精煉流程與連鑄鋼胚溫降，鋼胚外質良好並無直/橫向裂缺陷，優化製程結果使H13生產如同一般鋼種般順暢，可穩定多連鑄，進一步提升鑄胚得料率與品質，成功建立以一般煉鋼製程生產高階H13工模具鋼煉鑄之產製能力。

並列摘要

H13 tool steels have been manufactured almost exclusively from ingot-cast material because of poor continuous-castability. The main benefits of continuous casting over ingot casting are higher productivity and quality product. Great efforts have been made among special steel producers using continuous casting. Dragon Steel Co. produced H13 via a curved-mould continuous caster with a radius of 12.5m, and 4 strands in sizes of 200*480mm. The steel was melted in a 150t EAF from scrap and de-phosphorus hot metal. The molten steel was tapped into a ladle after the removal of slag and the LF process was extended to a proper melting of other alloys and desulphurization process. By the help of on-site rapid EDX analysis of steelmaking slag, sulphur content dropped to 0.001 wt% within 1hr. Then the molten steel was transferred to vacuum station with Ar injected. The degassing exercise helped the removal of nitrogen and hydrogen and enhanced the separation of non-metallic inclusions. At the casting station, numerically calculated cooling profile of bloom during continuous casting and elastic stresses and experimentally determined thermo-mechanical data of the H13 were used to determine a suitable secondary cooling strategy. A soft cooling pattern was used to maintain a surface temperature above 850℃ at straightening unit to avoid surface cracking. Compared to that with ingot-casting, continuous casting H13 had a 20% higher yield and profitability.

並列關鍵字

H13 ； tool steel ； Continuous casting ； Soft cooling ； SKD61