【摘要】 在 3 3× 10 0 s- 1 ～ 3 3× 10 - 5s- 1 范围内连续调整拉伸速率 ,测定了韧性、介韧性、脆性球墨铸铁的σb,δ及Ψ值。结果发现 ,随拉伸速率逐渐减小 ,上述性能指标先是逐渐增大 ,至某一最大值后又逐渐减小 ,所得曲线呈峰状 ,但三种球铁峰值及峰的形状有所不同。作为脆性金属材料的中硅球铁 (～ 5 %Si) ,在低拉伸速率时呈现出一定塑性 ,表明这类材料在慢拉伸条件下 ,其塑性尚有一定潜力。初步研究表明 ,慢拉伸时球铁的变形机制发生改变。更多还原

【Abstract】 Value of σ b, δ , Ψ were measured for several tough,quasi tough, brittle nodular cast irons at the tension rate 3.3×10 0s -1 to 3 3×10 -5 s -1 . σ b, σ 0 2 ,δ,Ψ with the reduction of tension rate, increase gradually and reach their maximum value, then decrease. The curves obtained are peak like, but shapes of these peaks are somewhat different. The nodular cast iron with a medium Si content(5%Si), known as a brittle metallic material, exhibits certain extent of ductility at lower tension rate, shows that this material has some potential in ductility at slow tension. Primary research indicates that deformation mechanism has changed at slow tension.更多还原