GCr15轴承钢300 mm×400 mm连铸坯1180～1260℃加热时间对Φ60 mm材带状组织的影响

Effect of Heating Time of Bearing Steel GCr15 300 mm × 400 mm Casting Bloom at 1180～1260℃ on Banded Structure of Φ60 mm Bar

GCr15轴承钢(/%:0.95～1.05C,0.20～0.30Si,0.30～0.40Mn,1.40～1.50Cr)300 mm×400 mm连铸坯的生产流程为120 t BOF-LF-RH-CC-连轧至Φ60 mm材。生产试验了连铸坯1 180～1 260℃高温扩散时间4.5～24 h对Φ60 mm热轧材碳化物带状的影响。结果表明,随保温时间的增加,热轧材带状级别降低,当保温时间为4.5～6.5 h、6.5～10 h和≥13 h时,Φ60 mm材的带状级别分别达2.5级、2.0级和1.5级。可根据不同带状级别要求,设定相应的保温时间。

The production flowsheet of 300 mm × 400 mm casting bloom of bearing steel GCr15 （/% ： 0. 95 ～1.05C, 0. 20 ～0. 30Si, 0. 30～0.40Mn, 1.40 -1.50Cr） is 120 t BOF-LF-RH-CC-continuous rolling to Ф60 mm products. The effect of high-temperature diffusion time 4. 5 ～ 24 h of casting bloom at 1 180 ～1 260 ℃ on carbide banded structure of Ф60 mm hot-rolled products has been tested. Results show that with increasing holding time the rating of banded structure of hot-rolled products decreases, and with holding time 4.5 ～6. 5 h, 6. 5 ～ 10 h and ≥13 h the rating of banded structure of Ф60 mm products is respectively 2. 5, 2. 0 and 1.5. It is available based on the requirement on different rating of banded structure to define the corresponding holding time.