銲前冷加工對AISI 316不?袗?機械性質之研究

The Study of Mechanical Properties on The Pre-Weld Cold Working of Stainless Steels 316

周文斌

指導教授 ： 屠名正 ； 周長彬

國立臺灣師範大學/科技學院/工業教育學系/碩士(2001年)

摘要

本研究選用AISI316沃斯田鐵型不?袗?為母材；母材採用對接方式進行銲接；氣體鎢極電弧銲（TIG）為銲接方式，銲前先施予不同冷加工度，分析其抗拉強度與微硬度等機械性質的改變，微觀金相結構與肥粒相指數等變化情形等問題深入探討。
研究結果顯示，無熱處理情況下，熱影響區及母材會隨冷加工度增加而為硬度值增加；經熱處理（1050℃、1Hr、空冷）後即無明顯變化。銲道之肥粒相指數並不隨冷加工度增加而變化；但在母材之肥粒相指數不管母材是否經熱處理，會隨冷加工度增加肥粒相指數增加，但經熱處理後銲道之肥粒相指數會降低。銲件拉伸破斷面經由SEM觀察，拉伸破壞原因係屬於延性破壞。

關鍵字

銲前冷加工 ； AISI 316不?袗?機械 ； 肥粒相指數

並列摘要

The purpose of this Research was to systematically study the weldability of stainless steel under Tungsten Inert Gas Arc Welding（TIG）.The base metals used was AISI 316 austenitic stainless steel with filler metal of ER308 in the type of plane joint. On the pre-weld different cold working of Stainless Steels 316 weldments were conducted. A series of experiments including tensile testing , microhardness testing , ferrite scope testing，optical metallography and SEM were used to determine and analyze the relationship between mechanical properties and microstructure.
A series of experiment results indicated that , non-heat treatment under , cold working increase that heat affected zone and base metal can improve the ultimate tensile strength , however post-weld with 1050℃ , 1 hour heat treatment can not obvious variation. Cold working increase the ferrite scope in the fusion zone not obvious difference , but the base metal was enhance , heat treatment can decrease the ferrite scope in the fusion zone. SEM observations on the tensile tested specimen showed a ductile fracture surface.

參考文獻

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