40CrV 

 40CrV, alloy structural steel. Uniform digital code: A23402. Standard: GB / T 3077-1988 
 Chemical composition 
 Mass fraction (%): C C: 0.37 ~ 0.44 Si Si: 0.17 ~ 0.37 Manganese Mn: 0.50 ~ 0.80 S S: to allow the residual phosphorus content ≤ 0.035 P: ≤ 0.035 to allow the residual content 
 Chromium Cr: 0.80 ~ 1.10 Ni: to allow the residual content ≤ 0.030 Copper Cu: ≤ 0.030 to allow the residual content of vanadium V: 0.10 ~ 0.20 
 Mechanical Properties 
 Sample size] [blank] 25mm [standard heat treatment hardening 880 ℃, oil-cooling; tempering 650 ℃, water-cooled, oil-cooling. [Mechanical Properties] Tensile strength σb (MPa): ≥ 885 (90) yield strength σs (MPa): ≥ 735 (75) Elongation δ5 (%): ≥ 10 Reduction of area ψ (%): ≥ 50 impacts Power Akv (J): ≥ 71 impact toughness αkv (J/cm2): ≥ 88 (9) Brinell hardness (HBS100/3000) (annealing or tempering state): ≦ 241 Delivery status: to heat treatment (positive fire, high temperature annealing or tempering) or heat treatment delivery, delivery status should be indicated in the contract. Hardening heat treatment standard] [880 ℃, oil-cooling; tempering 650 ℃, water-cooled, oil-cooling. Edit this paragraph the main features 
 Quenched and tempered steel with high strength and high yield point, the mechanical properties better than 40Cr. Cold plastic deformation and cutting are medium heat sensitivity is small, but tend to temper brittleness and sensitivity of white spots. General use in the quenched state. 
 Application examples 
 For the manufacture of variable load, high load all the important parts, such as locomotive connecting rod, crankshaft, putting, propeller, beams, bushings, brackets, studs, screws, not carburized gear, the nitriding treatment of the kinds of gears and pins, high-pressure boiler water pump shaft (diameter less than 30mm), high-pressure cylinders, steel and bolts (temperature less than 420 ℃, 30MPa) and so on. Good mechanical properties and process performance, high hardenability, adding vanadium to steel, grain refining, reducing heat sensitivity, increased strength and toughness, high fatigue strength, yield ratio is high, but poor welding cold plastic deformation due to the low. Is a relatively high spring, as large sections of the important spring and high-load operating temperature <300 ℃ of the valve spring, piston spring, valve spring