Impact Strength Of Steel Research Articles

Effect of previous corrosion on the impact strength of steel specimens with stress raisers of the screw-thread type in relation to the method of thread cutting

It has been established that the method of preparation of stress raisers has an effect on the impact strength and ductility of steel. It has been shown that previous corrosion in a 3% NaCl aqueous solution produces changes in the impact strength and ductility of notched specimens; this effect is especially pronounced in the initial stages of corrosion and less so in the later stages.

Impact strength of steel for rolls in hot rolling mills

Impact strength of steel for rolls in hot rolling mills

Effect of calcium silicide and rare earth metal additions on the ductility of structural steel

1. When added in the optimum quantities, rare earth metals cause a substantial increase in the ductility and impact strength of structural steel; their effect on the UTS of steel is negligible. 2. The effectiveness of these additions in increasing the impact strength of steel increases in the following order; calcium suicide; FTsM-5; mishmetal; lanthanum; yttrium. 3. Rare earth metals added in the optimum quantities refine the macrostructure of steel and change the character of fracture from brittle to ductile; at high concentrations of these additions the macrostructure becomes coarser and the fracture brittle.

Reasons for the high impact strength of steel containing rare earth metals

1. We found that the inclusions along the boundaries have different shapes in rolled 40KhNMA steel with and without ferrocerium. Probably this is one of the reasons for the difference is the impact strength of samples in the transverse direction. 2. We showed that the rare earth metals do not prevent inclusions along the grain boundaries.

New low carbon structural steels hardened by aging

1. Nickel steels (9–20% Ni) containing Al, Ti, or Mo together with Co are susceptible to aging and considerable hardening during a short period of tempering at 400–550°C (maximum hardening occurs at about 500°C). 2. The hardening of steels containing 9% Ni is accompanied by a drop of plasticity and ductility. In high-nickel steels (18–20% Ni) the plasticity and ductility do not decrease so much: δ=10–12%; ψ=∼60%; ak=5.0–6.0 kgm/cm2 after a strength of δb=150–170 kg/mm2 is reached, depending on the combination of the alloyed elements. 3. Sulfur and phosphorus sharply decrease the plasticity and ductility and the impact strength of steels containing 18–20% Ni with martensite which can be aged, and therefore the amounts of these impurities should be strictly limited to less than 0.010% of each. 4. High-nickel steels of both types with martensite which can be aged are characterized by a high resistance to brittle fracture; these steels are not susceptible to brittleness due to tempering, and are very little sensitive to cuts; they are hardenable in air to a depth of 200 mm. 5. Hardened steels with martensite which can be aged have a high fatigue resistance in both smooth and notched samples (70–72 and 28–30 kg/mm2 respectively).

Mechanical properties of steels with low hardenability after quenching and tempering at low temperatures

We measured the static bending strength, the hardness, and the impact strength of steels with low hardenability after induction heating followed by quenching and low-temperature tempering. We have recommended optimum quenching temperatures, tempering temperatures (in the case of induction heating), and the hardenability of steels for machine parts of different sizes. We have shown that the static bending strength and the impact strength of samples of quenched carbon steels are as high as those of case-hardened alloy steels.