15MnVNq鋼56mm厚板对接焊縫系用H08MnMoA焊絲和350焊剂的埋弧自动焊得到的。本試验利用J_R阻力曲綫法,在两种加載速率(8.33×10~(-8)和0.64～1.71mm/S)下测定了-75℃至室温范围內焊缝的J_(max)值。对15MnVNq鋼56mm厚板基材和对接焊缝的断裂韌性温度转变曲綫进行了比較。同时,在两种应变速率(5.56×10~(-4)和2.78×10~(-4) 1/s)下測定了非标准试件在-75℃至20℃温度范围內焊縫的σ_b,σ_5和P值。 15MnVNq steel 56mm thick butt-welded joints with H08MnMoA wire and 350 flux submerged arc automatic welding obtained. In this experiment, the J_ (max) value of the weld in the range of -75 ℃ to room temperature was measured by J_R resistance curve at two loading rates (8.33 × 10 -8 and 0.64 ~ 1.71 mm / S). The fracture toughness temperature transition curves of 15MnVNq steel 56mm thick slab and butt weld were compared. At the same time, the σ_b of the weld in non-standard specimen at -75 ℃ to 20 ℃ was measured at two strain rates (5.56 × 10 -4 and 2.78 × 10 -4 / 1) , σ_5 and P values.