Properties of low-pearlite steel with manganese

Conclusions

• 1. Raising the Mn concentration of low-pearlite steel from 0.4 to 1.8% leads to a considerable increase in strength (Δσ_b = 20kg/mm², Δσ_b = 16kg/mm²), the elongation remains unchanged (δ=32%), and the reduction in section increases (Δψ∼10%).

• 2. Alloying of low-pearlite steel with 0.4−1.5% Mn substantially improves the work of crack propagation in the ductile range (Δa _p=7 kg-m/cm²) and shifts the ductile-brittle transition temperature to the range of negative temperatures$\left( {\Delta T_{cr}^{a_{P_{2.0} } } = - 35^ \circ C} \right)$. The value ofa _p increases with up to ∼2% Mn as compared to the steel with 0.4% Mn.

  The percentage of ductile components in the fracture remains practically unchanged with the addition of up to 1.5% Mn, but decreases with larger amounts of Mn.

• 3. The work of crack initiation increases substantially (by ∼8 kg-m/cm²) for the steel with 1.3–2.3% Mn as compared to the steel with 0.4% Mn.

• 4. The strength of low-pearlite steel can be improved by alloying with up to 2% Mn, in which case σ_b ∼ 60 kg/mm², σ_T = 43 kg/mm² the work of crack initiationa _i∼9 kg-m/cm², and the work of crack propagationa ^ductile_p ∼7 kg-m/cm².

Alloying of low-pearlite steel with 1.5% Mn results in the highest resistance to crack propagation (a _p∼14 kg-m/cm²).