Chemical composition: C 0.35~0.45 Si 0.60 Mn 0.80 Cr 12.0-14.0 P 0.03 S 0.035 Mo - Available size : Round steel bar 60-800mm Flat steel bar 25-400mm*200-800mm Surface conditions: black surface/ grinded/ machined Mechanical properties : hardness: annealing, and 201 or less hb, indentation diameter of 3.9 ~ 4.3 mm; quenching, 50 or more hv Low heat treatment specification and metallographic organization: Annealing heat treatment specification: 1), 800 ~ 900 slow cooling or about 750 cold quickly; 2) quenching, 1050 ~ 1100 cold oil; 3) tempering, 200 ~ 300 cold fast. Metallographic organization: organizational characteristics for markov shape. Characteristics: 4 cr13 characteristics after quenching than 3 cr13 high hardness, good corrosion resistance Application : Rj, nozzle, valve seat, etc. 1 cr17ni2 features strong resistance to corrosion of nitric acid and organic acid. Use used for high hardness and high wear resistance of hot oil pump, valve, valves, bearings, medical equipment, spring, etc