固溶处理对S32168不锈钢管组织及性能的影响

Effect by Solution Treatment on Structure and Properties of S32168 Stainless Steel Pipe

研究了固溶处理温度对S32168不锈钢组织和力学性能的影响。结果表明:固溶处理后不锈钢为等轴晶粒,且存在退火孪晶;当固溶温度≥1080℃,不锈钢中的析出物全部溶解到基体中;固溶温度为1040~1120℃时,晶粒尺寸随温度的升高而长大,长大激活能为563.49 kJ/mol,且在该温度范围内,S32168不锈钢管的晶粒尺寸与室温力学性能符合Hall-Petch关系式,该不锈钢强化机制主要为细晶强化;随着温度的升高,S32168不锈钢的断裂方式由脆性断裂向韧性断裂转变。

Studied are the effects by the solution treatment temperature on the structure and mechanical properties of the S32168 stainless steel.As a result it is revealed that after the solution treatment the structure of the said stainless steel is composed by equiaxed grains,and there exist annealing twins;when the solid solution temperature is1080℃,the precipitates in the stainless steel are almost completely dissolved into the matrix;when the solid solution temperature is 1040〜1120℃,the grain size grows along with the increase of the temperature,and the growth activation energy is 563.49 kJ/mol,and within this temperature range,the grain size and the room temperature mechanical properties of the S32168 stainless steel conform to the Hall-Petch relationship:the stainless steel strengthening mechanism is mainly fine grain strengthening;and along with the increase of the temperature,the fracture mode of S32168 stainless steel is transforming from the brittle fracture to the ductile fracture.