Abstract: The Φ219 mm x 20 mm seamless tube of 09MnNiD steel (/% ；0.07 ~ 0.10G,0. 25 ~ 0.35Si, 1.35〜1.40Mn,0.49 〜0.51Ni,0.020 ~O.O35A1, ≤0. 02Nb, ≤0.015P, ≤0.006S) has been produced by 20 t EAF—LF + VD→ ingot casting —► rolling Φ270 mm round billet—► cross piercing → CPE rolling tube—► online normalization. By controlling EAF endpoint [C] ≤ 0.04% and [ P] W≤ 0. 008% , LF refining [S] ≤ 0.005% ,VD≤67Pa, 15 min, ingot cast steel overheating ≤ 45 °C , cooling rate of hot rolled piercing shell 30 ~70 P/min, and steel tube normalizing at 910 °C. The test results show that the microstructure is F + P, grain size grade 10, —70 °C impact energy KV2 3257 J, tensile strength 503 〜508 MPa,yield strength 354~356 MPa,and the chemical composition, mechanical properties, nondestructive testing meet the requirements of GB 150.2-2011 standard.

Key words:  , -70 °C , , 09MnNiD Steel, Φ 219 mm x20 mm Seamless Tube Online Normalization, Grain Refining

摘要： 按照20 t EAF→LF+VD→模铸3t钢锭→轧制Φ270 mm圆钢→斜轧穿孔→CPE轧管→在线常化工艺流程,生产Φ219 mm×20 mm 09MnNiD钢无缝管（/%:0.07～0.10C,0.25～0.35Si,1.35～1.40Mn,0.49～0.51Ni,0.020～0.035Al,≤0.02Nb,≤0.015P,≤0.006S）。通过控制EAF终点C≤0.04%和P≤0.008%,LF精炼S≤0.005%,VD≤67Pa,≥15 min,模铸过热度≤45℃,热轧后荒管冷却速度30～70℃/min,钢管常化温度910℃,开发了Φ219 mm×20 mm钢管。测试结果表明:生产的钢管显微组织为F+P,晶粒度10级,-70℃冲击功KV2≥275 J,抗拉强度503～508 MPa,屈服强度354～356 MPa,以及其化学成分、非金属夹杂物、无损检测均满足GB 150.2-2011标准要求。

关键词:  -70 °C 09MnNiD钢, Φ 219mmx20 mm无缝管在线常化, 晶粒细化