本文選題：奧氏體耐熱鋼　切入點(diǎn)：碳化物　出處：《材料熱處理學(xué)報(bào)》2017年02期 　論文類型：期刊論文

【摘要】：采用光學(xué)顯微鏡(OM)、能譜儀(EDS)、X射線衍射儀(XRD)、高溫顯微鏡原位觀察等實(shí)驗(yàn)手段,分析了ZG40Cr25Ni20奧氏體耐熱鋼燒損原因。結(jié)果表明,隨著溫度升高,奧氏體晶粒不斷長(zhǎng)大,碳化物Cr23C6不斷形成和長(zhǎng)大,碳化物中的Cr含量和碳化物硬度不斷增加,奧氏體基體中的Cr含量不斷減少。溫度過高,碳化物溶解,形成孔洞,促進(jìn)微裂紋沿晶界的擴(kuò)展,奧氏體晶粒間的結(jié)合力逐漸減弱,基體發(fā)生過燒,鋼的結(jié)晶組織遭到破壞,失去金屬原有的塑性和強(qiáng)度,造成高溫耐熱管失效,孔洞和微裂紋的形成及擴(kuò)展是材料失效的主要原因。此外,高溫顯微鏡原位觀察和熱處理實(shí)驗(yàn)結(jié)果表明,ZG40Cr25Ni20耐熱鋼中碳化物的溶解溫度為1030~1250℃。高溫顯微鏡原位觀察為碳化物溶解觀察和耐熱鋼失效分析提供了一種新的方法。
[Abstract]:The causes of burning loss of ZG40Cr25Ni20 austenitic heat-resistant steel are analyzed by means of optical microscope, energy spectrometer, EDS-X ray diffractometer and in situ observation of high temperature microscope. The results show that the austenite grain grows with the increase of temperature. The formation and growth of carbides Cr23C6, the increase of Cr content and hardness of carbides, the decrease of Cr content in austenitic matrix, the dissolution of carbides at too high temperature, the formation of pores, and the propagation of microcracks along grain boundaries. The adhesion between austenitic grains is gradually weakened, the matrix is overburned, the crystalline structure of the steel is destroyed, and the original plasticity and strength of the metal are lost, which results in the failure of the heat-resistant pipe at high temperature. The formation and propagation of pores and microcracks are the main causes of material failure. The in-situ observation of high temperature microscope and heat treatment experiment show that the dissolution temperature of carbides in ZG40Cr25Ni20 heat-resistant steel is 1030 ~ 1250 鈩，

本文編號(hào)：1600197