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对普通碳钢表面进行渗铝处理,可大大提高碳钢的抗高温氧化能力。渗铝钢曾成功地用于炭黑工业使用的高温空气预热器上。可是,由于操作等原因,出现了该空气换热管口因超温引起的环向开裂,对此,我们作了一系列研究。本文即是工作之一;从材料和焊接失效部位的金相组织进行研究。一、正常渗铝钢及其焊接部位金相分折从图1可明显地看到其截面由三层组成;纯铝层(厚约0.03～0.1mm);铝铁合金层(厚约0.1～0.2mm);基体组织(铁素体+珠光体)。钢材热浸后,表面有高浓度的铝覆层,如不经
Aluminized aluminum surface treatment of ordinary carbon steel can greatly improve the high temperature oxidation resistance of carbon steel. Aluminized steel has been successfully used in the high temperature air preheater used in the carbon black industry. However, due to operation and other reasons, appeared in the air heat exchanger nozzle due to over-temperature caused by circumferential cracking, which, we made a series of studies. This article is one of the work; from the material and welding failure of the microstructure of the site to study. First, the normal aluminized steel and welded parts of the metallographic fracture can be clearly seen from Figure 1, the cross-section consists of three layers; pure aluminum layer (about 0.03 ~ 0.1mm thick); aluminum alloy layer (about 0.1 ~ 0.2 mm); matrix organization (ferrite + pearlite). After hot-dip steel, the surface has a high concentration of aluminum coating, such as without