( 1. 江蘇科技大學(xué) 材料科學(xué)與工程學(xué)院， 鎮(zhèn)江 212003； 2．洛陽(yáng)船舶材料研究所， 洛陽(yáng) 471039)
摘 要: 通過(guò)5A30鋁合金不同焊縫形式、 幾何尺寸對(duì)接接頭疲勞試驗(yàn)， 以及焊縫余高存在時(shí)焊趾處的應(yīng)力集中系數(shù)的測(cè)定和理論計(jì)算， 研究了焊縫幾何特征對(duì)鋁合金焊接接頭疲勞性能的影響。 結(jié)果表明: 單面焊雙面成型和雙面焊對(duì)接接頭的疲勞性能相當(dāng)， 在循環(huán)次數(shù)為(1.7～1.8)×106時(shí)， 疲勞強(qiáng)度約為100 MPa； 焊縫余高的存在使接頭的疲勞性能明顯降低， 增大焊縫余高， 接頭疲勞性能顯著下降， 去除余高， 則可使接頭的疲勞壽命提高2～3倍； 厚度為4 mm板材對(duì)接接頭， 焊縫余高為1～2 mm時(shí)， 焊趾處的應(yīng)力集中系數(shù)較其他部位增大50％左右， 焊縫余高大于3 mm， 焊趾處的應(yīng)力集中系數(shù)可超過(guò)1.70。
關(guān)鍵字: 鋁合金； 焊接接頭； 焊縫余高； 疲勞性能
5A30 aluminum alloy welded joints
（ 1. School of Materials Science and Engineering,
Jiangsu University of Science and Technology,
Zhenjiang 212003, China;
2. Luoyang Ship Material Research Institute,
Luoyang 471039, China）
Abstract: Based on the fatigue testing of 5A30 aluminum alloy welded butt joints which have different weld types and geometrical dimensions, the measurement and calculation of stress concentration coefficients (Kt) at the toes of weld, the influence of weld geometrical features on fatigue properties of 5A30 aluminum welded joints was studied. The results show that the fatigue properties of single-welded butt joints and doublewelded butt ones are matched and the fatigue strength of theirs at (1.7-1.8)×106 cycle is about 100MPa. The presence of weld reinforcements (WRs) reduces the fatigue properties of welded joints. Heightening WRs can greatly lower the fatigue properties of welded joints and wiping out WRs can increase fatigue life twice or three times as much. When the weld reinforcements change between 1-2 mm, Kt at toes of weld of 4 mm thick plates are increased 50% comparing with other parts, and if the WRs is higher than 3 mm, Kt at weld toes of joints may exceed 1.70.
Key words: aluminum alloy; welded joint; weld reinforcement; fatigue property
