SRB+IOB对X100管线钢在常熟土壤模拟溶液中应力腐蚀开裂行为的影响  

Effect of SRB+IOB on the Stress Corrosion Cracking Behavior of X100 Pipeline Steel in Simulated Solution of Changshu Soil

作　　者：杨旭 孙福洋 YANG Xu;SUN Fu-yang(Xi'an Special Equipment Inspection Institute,Xi'an 710065,China)

机构地区：[1]西安特种设备检验检测院,陕西西安710065

出　　处：《材料保护》2021年第2期21-26,108,共7页Materials Protection

基　　金：国家市场监督管理总局科技计划项目(2017QK069)资助。

摘　　要：为了更好地研究管线钢在特定土壤模拟溶液中的应力腐蚀机理,证实MIC和SCC的协同性与相关性,采用慢应变速率拉伸(SSRT)试验研究了SRB+IOB对X100管线钢在常熟土壤模拟溶液中应力腐蚀开裂行为的影响。结果表明:X100管线钢母材和焊缝试样在无菌和有菌(SRB+IOB)环境下的宏观断口均为斜断口,断裂面与拉伸轴方向大致呈45°,无菌环境下的断口颈缩程度均明显小于有菌(SRB+IOB)环境。母材和焊缝断口在无菌环境下均为韧性+脆性混合型断口,呈现准解理形貌,具有较高的SCC敏感性;在有菌(SRB+IOB)环境下均为韧性断口,呈现韧窝形貌,具有较低的SCC敏感性,且低于无菌环境。无菌环境下断口侧面的SCC裂纹明显多于有菌(SRB+IOB)环境。SRB+IOB的存在抑制了X100管线钢的脆变,导致X100管线钢的SCC敏感性降低,其影响作用主要集中在材料的塑性。In order to better study the stress corrosion mechanism of pipeline steel in the specific soil simulation solution and confirm the synergy and correlation of MIC and SCC,the effect of SRB + IOB on stress corrosion cracking behavior of X100 pipeline steel in simulated solution of Changshu soil was investigated by slow strain rate tensile (SSRT) tests and SEM. Results showed that the macro fracture of base material and weld sample of X100 pipeline steel exhibited oblique fracture in sterile and SRB+IOB simulated solution and fracture surface was approximately 45° to the stretch axis direction. The degree of fracture necking in sterile simulated solution was significantly less than in SRB+IOB. The fracture of base material and weld sample exhibited high SCC susceptibility in sterile simulated solution and the fracture mode was toughness + brittle mixed fracture,which belonged to quasi-cleavage morphology. The fracture of base material and weld sample had lower SCC susceptibility in SRB+IOB simulated solution and the fracture mode was ductile fracture,which belonged to tough fossa morphology. The SCC cracks on the side of the fracture in sterile simulated solution were significantly more than in SRB+IOB. The brittle of X100 pipeline steel was suppressed and the SCC susceptibility was reduced by SRB+IOB,while the influence was mainly focused on material plasticity.

关 键 词：SRB+IOB X100管线钢 常熟土壤 应力腐蚀开裂 

分 类 号：TG172.4[金属学及工艺—金属表面处理]