李彦哲 1徐锴 1沈海琴 2喻朝飞 3周璐宽 3念林哲3
作者信息
- 1. 哈焊所华通(常州)焊业股份有限公司,江苏 常州 213102||中国机械总院集团哈尔滨焊接研究所有限公司,黑龙江 哈尔滨 150028
- 2. 中车戚墅堰机车有限公司,江苏 常州 213011
- 3. 哈焊所华通(常州)焊业股份有限公司,江苏 常州 213102
- 折叠
摘要
Abstract
The low-temperature impact toughness discrepancy of deposited metals from 316LMn-type stainless steel flux-cored wires at-196℃was investigated.A Cr-Ni-Mn three-factor and three-level orthogonal experimental design was em-ployed to prepare deposited metals with different alloy compositions.Combined with mechanical property testing,range analysis,analysis of variance(ANOVA),microstructural characterization,and fracture analysis,the effects of alloying ele-ments and their interactions on the low-temperature toughness and fracture behavior of deposited metals were systematically analyzed.The results indicated that Ni exhibited the greatest influence on the impact toughness at-196℃,with a range value of 26.67,followed by Mn(14.00)and Cr(7.33).ANOVA results demonstrated that Ni had the most significant effect(F=291.35,P=0.0004),while Mn also showed a significant influence(F=79.14,P=0.0030).Furthermore,the Cr-Ni and Cr-Mn interactions were found to significantly affect the low-temperature impact properties.The theoretical optimized composi-tion was determined as Cr 22 wt.%,Ni 20 wt.%,and Mn 7 wt.%.The regulation of alloy composition resulted in significant changes in the solidification microstructure and phase constitution of the deposited metals,leading to variations in low-temperature toughness among different specimens.The WM-4 specimen was mainly composed of fine,uniformly distrib-uted cellular crystals and equiaxed grains,whereas the WM-6 specimen exhibited coarse columnar grains,localized δ-ferrite regions,and abundant Mn-Si-O complex inclusions.Fracture analysis revealed that the WM-4 specimen exhibited a typical ductile fracture dominated by dense dimples,indicating superior plastic deformation capability.In contrast,the WM-6 speci-men showed a mixed fracture mode combining ductile fracture and quasi-cleavage fracture.The high-Cr/low-Ni δ-ferrite re-gions facilitated the formation of quasi-cleavage facets and transgranular secondary cracks,which were identified as the pri-mary factors responsible for the deterioration of low-temperature impact toughness.Meanwhile,inclusions acted as preferen-tial sites for local crack initiation and contributed to the low-temperature fracture behavior.The findings provide a basis for the precise compostion design of austentic stainless steel welding material for cryogentic service.关键词
316LMn不锈钢/药芯焊丝/合金元素/低温冲击韧性/凝固组织/断裂行为Key words
316LMn stainless steel/flux-cored wire/alloying elements/low-temperature impact toughness/solidification mi-crostructure/fracture behavior分类
矿业与冶金
