【摘要】 以00Cr25Ni7Mo4N铸造不锈钢的组织和性能为研究内容,试验了Zr、Y和Ba-Ca变质剂对钢的变质效果。试验表明,3种变质剂对抑制晶体长大,细化组织,改善铸造性能和提高材料的力学性能均产生良好效果;其中Y的变质效果最为显著,试样的断口宏观形貌得以明显改善,断口撕裂的颗粒细化程度是未处理试样的1/11;组织中孤立岛状的γ相明显圆钝和尺寸变小;夹杂物数量减少;因此,钢的流动性提高,铸造工艺性能得以改善,铸造缺陷减少;由于钢的组织细化,力学性能明显提高。变质后的材料在具备良好塑韧性(δ=19%)时,σb和σs分别提高了16.1%和41.2%。更多还原

【Abstract】 Effects of Zr,Y and Ba-Ca modifier on microstructure and properties of 00Cr25Ni7Mo4N stainless steel were investigated.The results show that castablity and mechanical properties of the stainless steel are greatly improved with the modifier addition as a result of refining grain size by inhibiting grain growth.Y modifier exhibits the most desirable modification effects,where fracture macro-shape is apparently improved,and grain size in fracture position is refined by 91% of un-treated samples.Meanwhile,isolated γ phase in the microstructure of the modified steel is obviously spheroidized and refined,and inclusions are decreased,leading to the increase of liquid steel fluidity and improvement of properties and elimination of the related defects.Mechanical properties of the modified steel are obviously improved as a result of refinement of microstructure,where tensile strength and yield strength are increased by 16.1% and 41.2%,respectively,with the desirable elongation of 19%.更多还原