底材和退火对纳米/微米晶复合304不锈钢组织和力学性能的影响

Effects of substrates and annealing on the structure and mechanical properties of nano/micro-crystalline composite 304 stainless steel

通过铝热反应熔化法在铜底材和玻璃底材上制备块体纳米晶/微米晶复合的304不锈钢,研究了不同底材和退火工艺对钢的组织和力学性能的影响。研究发现2种底材上制备的不锈钢均包含纳米晶和微米晶,铜底材和玻璃底材上制备的材料的晶粒尺寸分别为28.8nm和30.0 nm,退火后变为21.4 nm和22.7nm。铜底材上制备的304不锈钢抗拉强度,屈服强度和伸长率分别为521 MPa,279 MPa和8.1%,退火后分别为1 001 MPa,475 MPa和9.3%。玻璃底材上制备的304不锈钢抗拉强度、屈服强度和伸长率分别为358 MPa,221 MPa和7.5%,退火后分别为1 023 MPa,461 MPa和8.6%。表明等温退火能够提高纳米晶/微米晶复合304不锈钢的性能。

Bulk nano/micro-crystalline composite 304 stainless steels were prepared by an aluminothermic reaction casting method.The effects of different substrates and annealing process on the mechanical properties of steels were investigated.It is found that the steels on two kinds of substrates consist of a nano/micro-crystalline dual-phase.The average grain sizes on copper and glass substrates are 28.8 and 30.0 nm,and become 21.4 and 22.7 nm,after the isothermal annealing.The tensile strength,yield strength and tensile ductility are 521 MPa,279 MPa and 8.1%,and become 1 001 MPa,475 MPa and 9.3%,after the isothermal annealing for the steel prepared on the copper substrate.For the steel prepared on the glass substrate,the above values are 358 MPa,221 MPa and 7.5%,and change to 1 023 MPa,461 MPa and 8.6%,after the isothermal annealing.It is demonstrated that the isothermal annealing treatment can improve the mechanical properties of steels.