31.75mm厚规格X65M管线钢的开发

Development of X65M Pipeline Steels with 31.75 mm Thickness

以低碳微合金设计为基础,采用洁净钢冶金技术,通过两阶段轧制和ACC层流冷却工艺来保证钢板的强度和高韧性,济钢开发了厚规格X65M管线钢。钢板具有针状铁素体和贝氏体混合组织,屈服强度470~520 MPa,抗拉强度600~700 MPa,屈强比0.76~0.85;-60℃夏比冲击功均值在290 J以上,-20℃DWTT在90%以上,各项性能指标满足标准要求。结合新开发的制管工艺,使批量生产的厚规格X65M焊管具有充足的强度富裕量、高的低温韧性和焊接性能。

Based on design of the low carbon micro alloy, the X65M pipeline steel with 31.75 mm thickness was developed in Jinan Steel. By using clean steel metallurgy technology, two stage rolling and ACC laminar cooling process, the strength and high toughness of heavy gauge X65M pipeline steel were ensured. The steel has a mixture microstructure of acicular ferrite and bainite, the yield strength of the plate ranged from 470 MPa to 520 MPa, tensile strength of the plate ranged from 600 MPa to 700 MPa, the Rt0.5/Rm were 0.76-0.85; the Charpy impact energy at-60 ℃ were more than 290 J, the DWTT at-20 ℃ were more than 90%, the all performance indicators can meet the standard requirements. With the development of new manufacturing process, the thick X65M welded pipe had rich strength, higher low temperature toughness and better welding property.