热处理工艺对F550海洋平台用钢组织与性能的影响

通过对不同淬火、回火工艺处理后的F550海洋平台用钢的力学性能、断口形貌、微观组织等进行分析,探讨了淬火、回火工艺参数对钢板性能及组织的影响。结果表明,淬火温度越高,组织晶粒越细小;随回火温度的升高,组织粗化,位错密度减少,钢板强度降低,塑性和韧性提高。16mm厚F550钢板最佳调质工艺为:880℃×120min淬火,630℃×220min回火。调质处理后钢板组织为粒状贝氏体+少量板条铁素体,屈服强度580MPa,抗拉强度660MPa,断后伸长率23%,-60℃冲击功稳定在210J以上。

Development of High Quality Casting Roll for Steel Pipe Straightening and Cold Roll Formed Steel

Abstract： Through multialloy strengthening modification treatment, Shandong Province Sifang Technical Development Co., Ltd. has developed high quality casting roll which make a feature of high C, Cr, Ni and Mo content. The basic microstructure of material is austenite, bainite and martensite, the carbide is mainly M7C3 and its content is about 20%, the micro hardness is up to HM 1 800, the microstructure is appeared as no continuous stripe state, block state, particle atate and chrysanthemum state, the tensile strength is 540 MPa, the impact toughness is 7.5 J/cm2, the hardness distanced 120 mm from surface is HRC 59.3. The utilization coefficient of material for producing roll is up to above of 77.5%. The article also point out that the developing trend of roll process is toward high clualitv, high alloying, reolaced for~in~ by castint~, and bimetal structure, etc.