FV520B不锈钢激光熔覆热影响区组织演变及其对力学性能的影响

发布时间：2018-05-27 20:23

本文选题：激光熔覆 + 热影响区　；参考：《金属学报》2016年01期

【摘要】：对FV520B不锈钢零件的激光熔覆热影响区进行了组织特征分析,结合过冷奥氏体连续冷却转变(CCT)实验、模拟热影响区拉伸及冲击实验,研究了热影响区组织及力学性能的演变规律和机理.结果表明,热影响区可以按照组织演化特点分为4个特征区域:半熔区(A区),析出相溶解区(B区),完全奥氏体化区(C区)和部分奥氏体化区(D区).各区域均为马氏体组织,靠近界面区域的组织较为粗大,第二相发生溶解,硬度更高,固态相变点更低;距界面稍远区域回火马氏体增多,第二相未溶解,但有长大的趋势,硬度较低,固态相变点较高,接近原始材料.决定激光熔覆热影响区组织及力学性能的最主要因素是热循环的最高温度,最高温度越高,强度损失越大,固态相变点越低,相应硬度越高,延伸率及冲击功降低.
[Abstract]:The microstructure characteristics of laser cladding heat affected zone (HAZ) of FV520B stainless steel were analyzed. Combined with the continuous cooling transformation experiment of undercooled austenite, the tensile and impact tests of the HAZ were simulated. The evolution law and mechanism of microstructure and mechanical properties of heat affected zone were studied. The results show that the heat affected zone can be divided into four characteristic regions according to the characteristics of microstructure evolution: the semi-melting zone (A), the precipitated phase dissolution zone (B), the complete austenitization zone (C) and the partial austenitization zone (D). Each region is martensite structure, the structure near the interface area is coarse, the second phase dissolves, the hardness is higher, the solid phase transformation point is lower, and the tempering martensite increases slightly away from the interface, but the second phase is not dissolved, but has the tendency of growing up. The hardness is lower and the solid phase transition point is higher, which is close to the original material. The most important factor to determine the microstructure and mechanical properties of the laser cladding heat affected zone is the highest temperature of the thermal cycle. The higher the maximum temperature, the greater the strength loss, the lower the solid phase transition point, the higher the hardness, the lower the elongation and the lower the impact energy.
【作者单位】：装甲兵工程学院装备再制造技术国防科技重点实验室;哈尔滨工业大学先进焊接与连接国家重点实验室;
【基金】：国家重点基础研究发展计划项目2011CB010403 装备再制造技术国防科技重点实验室基金项目9140C85040314OC85353资助~~
【分类号】：TG174.4

【相似文献】