加热温度对S30432奥氏体不锈钢管内壁喷丸层的影响

Effect of heating temperature on shot blasting layer of S30432 austenite stainless steel tube

借助扫描电镜及能谱仪等,研究不同热处理温度（740、760、780、800、820、850和1000℃）对S30432不锈钢管内壁喷丸层的影响。结果表明：喷丸层硬度随着热处理温度的提高而逐渐降低。当热处理温度达到810℃时,喷丸层硬度与基体硬度平均差值为100 HV0.5;温度至1000℃时,喷丸层消失。在740~770℃温度范围,喷丸层仍保持良好的向外表面输送Cr元素的能力;在800~850℃温度范围,喷丸层的形变组织不同程度退化,向外表面输送Cr元素的能力降低。为了保证喷丸层组织和抗氧化性能不被破坏,确保喷丸处理的质量,首先应避免对内喷丸钢管进行1000℃以上的固溶处理,其次应保证内喷丸钢管焊后热处理温度不超过780℃。

The effect of heat treatment temperature（ 740,760,780,800,820,850 and 1000 ℃） on shot blasting layer of S30432 stainless steel was investigated by means of scanning electron microscope（ SEM） and energy dispersive spectrometer（ EDS）. The results show that the hardness of shot-blasted layer decreases with the increase of temperature. The average hardness difference between the base and the shotpeening layer is 100 HV0. 5 when the heat treatment temperature is 810 ℃,while the shot-peening layer disappears completely at 1000 ℃.The shot-peening layer still keeps good transporting capacity of Cr element to the external surface between 740 ℃ and 770 ℃,while the deformed microstructure and the Cr transporting capacity of shot-blasted layer is degraded in the range of 800-850 ℃. In order to guarantee the microstructure and oxidation resistance of shot peening layer,so that to ensure the shot-blasted quality,the solution treatment above 1000 ℃should be avoided and the post welding heat treatment temperature for the inside shot blasting steel tube should be lower than 780 ℃.