麻田散鐵不銹鋼鑄件回火組織與中/低溫衝擊韌性研究

Study of Medium/Low Temperature Impact Toughness and Tempered Structure of Martensitic Cast Stainless Steel

許正勳(C. H. Hsu) ； 李深智(S. C. Lee) ； 鄧惠源(H. Y. Teng) ； 陳鴻銘(H. M. Chen)

《材料科學與工程》 33卷2期 (2001/06) Pp. 105-110

https://doi.org/10.6409/JMSE.200106.0105

摘要

本研究係探討CA-15麻田散鐵不銹鋼鑄件，經沃斯田鐵化與回火處理後，材料組織改變及中／低溫衝擊韌性變化的情形。由實驗得知，鑄態CA-15麻田散鐵不銹鋼，在肥粒鐵與麻田散鐵品界上，形成厚薄不一的高鉻碳化物薄層，造成材料衝擊吸收能量值偏低與離散，材料經沃斯田鐵化後，碳化物薄層重濟回基地而消失。回火處理後經X光繞射分析得知，殘留沃斯田鐵在400℃回火時已分解完成。同火於200~350℃時發生二次硬化現象。中溫衝擊韌性較常溫衝擊韌性呈比例上升趨勢，且回火脆性發生在400℃左右，低溫衝擊韌性顯著降低，且對回火溫度的影響不大。

關鍵字

麻田散鐵不銹鋼 ； 回火組織 ； 中/低溫度 ； 衝擊韌性

並列摘要

This research studied the effects of quenched and tempered microstructure on the medium and low temperature impact toughness of grade CA-is martensitic stainless steel. It was found that carbide film formed around martensite and ferrite grain boundries in the as-cast structure of CA-is alloy which impact energy absorbed capacity of the material and also made it quite randomly distributed. Tempering above 400℃ dissolved all retained austensite in the matrix as confirmed by X-ray diffractometry. Secondary hardening occurred when the specimens were tempered in between 200-350℃. When tested at intermediate temperature, impact toughness increased proportionally to that of the ambient data and the tempered embrittlement phenomenon occurred at about 400℃. When tested at sub-zero temperature, impact toughness of the specimens were greatly reduced and did not affect much by the differences in tempering temperatures.

並列關鍵字

Martensitic stainless steel ； Tempered structure ； Medium/low temperature ； Impact toughness