采用中频感应局部加热弯管工艺试制了相对弯曲半径为1.8、弯曲角度为70°、规格为790 mm×30 mm的16Mo3钢大直径大变形量弯管, 并对试制的弯管进行了整体性检验、显微组织检验与力学性能试验。结果表明: 弯管弯曲部分的波浪度、圆度、壁厚减薄率均满足相关标准要求, 弯管显微组织为铁素体＋珠光体＋少量碳化物, 无晶间裂纹; 室温拉伸性能、冲击性能及500 ℃高温拉伸性能也均符合标准要求; 弯管各部位的力学性能均匀, 且与原始管材的性能处于同一水平。

The large-diameter and large-deformation 16Mo3 steel pipe bend was made by means of the middle-frequency induction bending procedure through heating a narrow circumferential band around the pipe, of which the pipe size was 790 mm×30 mm, the relative bend radius was 1.8 and the bend angle was 70°. The pipe bend was inspected and then sampled to examine the microstructure and test the mechanical properties. The results showed that the wave shape degree, ovality and wall thinning rate of the bending portion could meet the requirement of the corresponding standard, the microstructure of the bend was ferrite+pearlite+little carbide and no intergranular cracks, tensile and impact properties in room temperature and 500 ℃ tensile properties were in accordance with the corresponding standard, the test results of the pipe bend mechanical properties in different location of the bending portion were uniform and in the same level as the pipe raw material properties.