控轧控冷工艺参数对X65管线钢显微组织的影响

Effect of Controlled Rolling and Cooling Process Parameters on Microstructure of Pipeline Steel X65

应用Gleeble-3500热/力模拟试验机研究了轧后冷速(20～0.5℃/s)、卷取温度(630～500℃)、精轧初始温度(1 000～900℃)、末道次精轧温度(860～750℃)对X65管线钢(0.08%C、1.38%Mn、0.032%Nb、0.041%V、50×10^(-6)N)显微组织的影响。结果表明,增加轧后冷却速度、减小950℃左右的压下量,降低终轧和卷取温度可细化板材组织。提出150 mm×1 700 mm板坯轧成7.1 mm成品板的轧制温度为:1 150～1 200℃加热,≤1 130℃粗轧至35 mm,950～1 020℃精轧,≤830℃终轧,≤580℃卷取,其产品力学性能满足标准要求。

Effect of cooling rate after rolling （20 - 0. 5 ℃/s）, initial pass temperature of finishing rolling （ 1 000- 900 ℃ ）, last pass temperature of finishing rolling （ 860 - 750 ℃） and coiling temperature （ 630 - 500 ℃ ） on mierostructure of pipeline steel X65 （0. 08% C, 1.38% Mn, 0. 032% Nb, 0. 041% V, 50 × 10^-6 N） has been studied by using Gleeble-3500 thermal-mechanical simulator. Results showed that with increasing cooling rate after rolling, decreasing reduction ratio at about 950 ℃, decreasing finishing and coiling temperature, the microstructure of plate products was finer. The rolling temperature for 7. 1 mm finished plate rolled by 150 mm × 1 700 mm slab was proposed that 1 150 - 1 200 ℃ heating, rough rolling ≤1 130 ℃ to 35 ram, initial pass finishing rolling 950 - 1 020℃, last pass finishing rolling ≤830 ℃ , and coiling ≤580 ℃ , and the mechanical properties of products met the requirement of standard.