高強度IF鋼片之開發

Development of High Strength IF Steel Sheets

陳煌湶(H. C. Chen) ； 黃議興(Y. S. Hwang) ； 洪偉仁(W. R. Horng)

《鑛冶：中國鑛冶工程學會會刊》 39卷2期 (1995/06) Pp. 27-36

摘要

本研究主要在極低碳（0.003% Cl）加Ti之IF鋼中，添加0.08%P後，再添加不同含量之Si、Mn、Nb、B等元素，以探討成份及製程對於冷軋鋼片機械性質、二次加工脆性及點銲強度的影響。Si、Mn之添加均會提高鋼片之抗拉強度及銲核強度。Si、Mn存在一適當之添加量，使得鋼片達到最高r值。加Nb及B對於鋼片之機械性質或點銲性質沒有顯著的影響，但加B可以大幅降低鋼片轉脆溫度因而改善鋼片二次加工脆性。升高盤捲溫度後，將降低鋼片r值，升高退火溫度後，將提高鋼片轉脆溫度，此與鋼片中（Fe.Ti）P析出物之大小及分佈有關。提高冷軋率後將提高鋼片r值，是因為鋼片中｛111｝再結晶集合組織增強之故。綜合上述結果，選擇適當的成份及製程，可開發40kg／mm^2級高強度IF鋼片。

並列摘要

The effects of Si, Mn, Nb, and B additions and process parameters on the mechanical properties as well as cold-work brittleness and spot weldabilit y of the Ti and P modified extra-low-carbon (0.003%C) steels were investigated. Si and/or Mn addition in steel increases tensile strength in both matrix and weld nugget. There exists optimum contents of Si and Mn to obtain high r value. Nb and /or B has little effect on the mechanical properties and weldability. B addition decreases transition temperature and improves resistance to cold-work brittleness. Increasing coiling temperature decreases r value, while increasing annealing temperature increases transition temperature. This could be attributed to the size and distribution of (Fe.Ti)P precipitates. Increasing cold-rolled reduction improves r value because of stronger {111} recrystallization texture.High strength IF steels with tensile strength around 40kg/mm^2 could be developed with proper alloying and processing conditions.