On the influence of laser cladding and post-processing strategies on residual stresses in steel specimens
On the influence of laser cladding and post-processing strategies on residual stresses in steel specimens
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DOI：
10.1016/j.phpro.2014.08.169
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
H. Köhler;R. Rajput;P. Khazan;J. Kornmeier
中科院分区：
文献类型：
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作者：
H. Köhler;R. Rajput;P. Khazan;J. Kornmeier
激光熔覆过程中的热循环会显著改变原始零件的力学性能。在循环加载零件的情况下，残余应力被怀疑是强烈决定疲劳寿命的特性。因此，本文用中子衍射法确定了处理策略和后处理策略对残余应力的影响。在这项研究中考虑了一种低合金钢和一种高合金钢，这两种钢都熔覆了钴基高温合金Stellite 21。对激光退火法和深轧法的加工速度和后处理进行了测试。低合金钢中的残余应力对应用的处理策略表现出高度的敏感性。在本研究中，深轧只在零件表面附近产生残余压应力。在高合金钢中，这一区域的压应力是激光熔覆后直接产生的，其大小取决于加工速度。在这两种代表性的钢中，可以获得一种可能对疲劳强度有利的压缩残余应力状态。
Thermal cycles during laser cladding can alter mechanical properties of the original part significantly. In case of cyclically loaded parts residual stresses are suspected to be a property strongly determining fatigue life. Therefore, in this paper the influence of processing and post-processing strategies on resulting residual stresses are determined by neutron-diffraction. A low-alloy as well as a high-alloy steel have been considered within this study, both cladded with the Co-based superalloy Stellite 21. Processing speed and post-treatment by laser annealing and by deep rolling strategies have been tested. Residual stresses in low-alloyed steel show high sensitivity on applied treatment strategies. In the present study only deep rolling induced compressive residual stress close to the part surface. In high-alloy steel compressive stress in this area resulted directly after laser cladding, where its magnitude depends on processing speed. A compressive residual stress statewhich is suspected to be beneficial for fatigue strength could be achieved at the two representative steels.