鉬對18－Cr肥粒鐵不銹鋼機械性質之影響

Effects of Molybdenum on Mechanical Properties of 18-Cr Ferritic Stainless Steels

蔣偉仁(Wei-Ren Chiang) ； 黃祺祥(Chi-Shang Huang)

《鑛冶：中國鑛冶工程學會會刊》 46卷1期 (2002/03) Pp. 78-84

https://doi.org/10.30069/MM.200203_46(1).0008

摘要

本文目的在利用添加不同鉬含量來探討其對18Cr不銹鋼機械性質之影響。家用熱水器經常在銲接處因腐蝕而損壞，所以改善銲道處之耐蝕性很重要，鉻可改善肥粒鐵不銹鋼之耐蝕性，但是添加鉬更為有效，鉬亦可改善高溫強度。434型不銹鋼就是於430型肥粒鐵不銹鋼添加1%Mo之改良型，其在氯化物環境中之耐蝕性較430型為優。於434型不銹鋼中再添加1%Mo即為18Cr-2Mo不銹鋼，其對氯化物與應力蝕裂之耐蝕性較434型為優。因此，18Cr-2Mo肥粒鐵不銹鋼可用於熱交換器，加熱器，熱水器及凝結器管。目前444型肥粒鐵不銹鋼在國內尚未生產，由於頗具市場潛力，實有及早研究之必要。

關鍵字

孔蝕 ； 間隙腐蝕 ； 應力蝕裂 ； 銲接性

並列摘要

The goal of this proposed research is to investigate the effects of molybdenum content on the mechanical properties of 18-Cr ferritic stainless steels. In household hot -water tanks, corrosion failure is concentrated at welded joints. It is important to improve the corrosion resistance of welded joint. The pitting resistance of the ferritic alloys can be improved somewhat with addition of chromium but alloying with molybdenum is much more effective. Molybdenum is also effective for improving high temperature strength. AISI type 434, the 1% molybdenum modification of type 430 ferrite stainless steel, possesses a resistance to corrosion in chloride environments superior to the basic grade. The additional 1% molybdenum in the 18Cr-2%Mo grade results in further improvement of corrosion resistance over that of type 434 particularly resistant to chloride and to stress-corrosion cracking. Applications for the 18Cr-2Mo ferritic stainless steel include heat-exchanger feedwater heater and condensor tubing. Until now type 444 ferritic stainless steel has not been produced in Taiwan. Owing to the potential market of this steel it is worthy to study it.

並列關鍵字

Pitting ； Crevice ； Stress corrosion crack weldability