回火软化性

This welding wire not only has the inherent properties of metal powder-cored wire, such as with better welding quality, without slag, highly efficiency and conveniently adjusting the alloying elements etc., but also has the advantage of low hardness in as-welded (less than HRC45), good machinability, high hardness in as-aged (more than HRC55) and better wear resistance with customary working procedure on making or repairing equipments such as rollers when reasonable designing the alloys content. The author adequately makes use of the high-tempering in the required stress relieving working procedure. During this working procedure, which causes the hardness of overlaying metal increased by the reason of austenite changes into tempered martensite and more chiefly what is the precipitation of a lot of carbide by secondary hardening simultaneously. This wire can solve the hard rolled problems of some solid wires with higher alloys while it can get over the conflict of existing overlaying materials what are always possesed high hardness with poor machinability or low hardness, good machinability with poor wear resistance. Further, it also can overcome the intenerating phenomena between welding beads and make the external hardness of overlaying metal uniform. Be sure it could be found important meaning in the overlaying of wear-resistant equipments, such as the precise roller.

该焊丝除了具有金属粉型药芯焊丝焊接质量好、无渣、高效率和合金成分可方便调节等固有的优点外，合理的设计粉芯中的合金成分，按通常工序制造与修复轧辊等设备，充分利用必需的消除应力工序的高温回火，堆焊层金属在奥氏体转变为回火马氏体的同时更主要是通过二次硬化析出了大量碳化物导致硬度增加，使得该焊丝还具有焊态硬度低(小于HRC45)、机加工性能好和时效态硬度高(大于HRC55)、耐磨性能好等优点，解决了某些高合金实芯焊丝轧制困难的问题，同时克服了现行堆焊材料硬度高、加工性能差或者硬度低、加工性能好、耐磨性差的矛盾，并能克服焊道之间的软化现象，使堆焊表面硬度较为均匀，对耐磨件，譬如精轧辊的堆焊具有重要意义。

Objective: To study the effect of polycythemia on blood oxygen saturation.

裴蕾目的：观察RBC剧增而引起的高粘血症对血氧饱和度的影响。

Based on SIMPLER algorithm in the curvilinear body-fitted coordinates, the calculations were performed for Pr=0.7, Re=10~1000 on non-orthogonal non-staggered grids which are generated by elliptic equation systems.

采用曲线坐标系下压力与速度耦合的SIMPLER算法，数值研究了周期性渐扩渐缩波纹通道内脉动流动与换热情况，流动Re数的范围为10~1000，Pr数为0.7。