摘要
设计一种新型中碳高硼铁合金,研究了淬火工艺对其淬火前后的显微组织和性能的影响。结果表明:中碳高硼铁合金铸态组织由珠光体、硼碳化合物以及马氏体组成,硼碳化合物以M_(23)(B,C)_6为主,并含有少量M(B,C),M_3(B,C)和M_2(B,C),体积分数为31.3%。在950℃、1000℃、1050℃和11 00℃淬火,其基体组织转变成马氏体,并含有少量残余奥氏体,体积分数分别为3.5%、4.0%、4.6%和5.4%。在950-1100℃淬火,硼碳化合物的类型不变,局部溶解,出现断网现象,在不同温度淬火后硼碳化合物的体积分数分别为30 6%、29.1%、27.3%和26.4%;随着淬火温度的提高,基体中合金元素的固溶量增加,硼碳化合物逐渐减少,从而减轻了对基体的割裂作用。淬火后,中碳高硼铁合金的硬度和冲击韧性显著提高,在950—1100℃淬火后,冲击韧性提高,硬度呈现先增加后减小的趋势。
A type of medium carbon high boron iron-base alloy was designed, and the microstructure and property before and after quenching were investigated. The results show that the microstructure of the as-cast medium carbon high boron iron-base alloy consists of pearlite （P）, martensite （M） and borocarbide. The volume fraction of borocarbide, which was mainly composed of M23（B, C）6, M3（B, C）, M （B, C） and M2（B, C）, was 31.3%. After quenched at the temperature of 950, 1000, 1050 and 1100 ℃, the matrix microstructure changed into martensite with a small amount of residual austenite content of 3.5%, 4.0%, 4.6% and 5.4% respectively. There was no change on borocarbide type, but the network pattern of borocarbide was broken because of partial dissolution. The volume fraction of borocarbide after quenching at the four temperatures were 30.6%, 29.1%, 27.3% and 26.4% respectively; With raising of quenching temperature, the amount of solid-solution alloy elements in matrix increased, and the borocarbide reduced gradually, therefore the separation effect to the matrix was reduced. The hardness and impact toughness of the alloy after quenching were significantly enhanced. After quenching at 950-1100 ℃, the hardness increased firstly and then decreased with quenching temperature, while the impact toughness consistently raised.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2013年第1期65-69,共5页
Chinese Journal of Materials Research
基金
国家自然科学基金(51261013
51171073)
云南省省院省校科技合作专项(2010AD012)资助项目~~
关键词
金属材料
中碳高硼铁合金
硼碳化合物
显微组织
淬火
硬度
冲击韧性
metallic materials, medium carbon high boron iron-base alloy, borocarbide, microstruc-ture, quenching, hardness, impact toughness
