The heat treatment temper of commonly used steel is calculated

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The temper hardness of steel (H) depend on temper temperature (T) with temper time (T) , 3 person between the function with existing particular concerns, namely H=f (T, t) . When T is calm value, the function relation of H and T can differentiate for 4 sort model: (1) linear model; (2) parabola; (3) power function; (4) of function of linear He Mi compound model. Because of hind when two kinds of types are being used, computation and constructive very disadvantageous, below circumstance of reason great majority, its brief melt into is mixed point-blank parabola, with classics proved recipe Cheng Ke expresses to be: H=a1+k1T 　 　 H=a2+k2T among them, a1, A2, K1, K2 is specific coefficient. According to practical technology experiment and the data of concerned bibliographical reference, apply several manage statistic to the method is calculated and be amended, the temper equation that reachs commonly used steel plants the part. Carry out a proof, these experience formula have fundamental applicable value. Steel grade quenchs temperature / quench H=62- of 　 of water of 45 840/ of medium temper equation (1/9000) H=50- of oily 　 of T220Cr 　 890/ (2/45) H=64- of oily 　 of T38CrMoAl 　 930/ (1/25) T (T<550) H=95- (1/10) T (T>550) H=75- of 　 of oil of 40Cr 　 850/ (3/40.

7- (1/11) H=69- of oily 　 of TCrWMn 　 830/ (1/25) H=64- of oily 　 of TCr12 　 980/ (1/80) T (T<500) H=107.

5- (1/10) T (T>500) H=65- of oily 　 of 1000/ of Cr12MoV 　 　 (1/100) T (T<500) H=69- of oily 　 of 9CrSi 　 865/ (1/30) H=72 of oily 　 of T5CrNiMo 　 855/ .

5- (1/16) H=69- of oily 　 of 855/ of T5CrMnMo 　 　 (3/50) H=93- of oily 　 of 1280/ of TW18Cr4V 　 　 (3/31250) H=733- of oily 　 of T2GCr15 　 850/ (2/3) T service instruction: (1) composition of chemistry of requirement raw material and mechanical function accord with national technology standard (GB, YB) , the biggest outside classics (or opposite ply) be close to or be less than quench critical diameter. (2) fall in the condition that quenchs time of temperature, temper is calm value, temper equation applies to convention to quench only, temper craft; Not usable Yuyawen quenchs, the craft such as compound heat treatment, deformation heat treatment. (3) in heat treatment process, still should choose to quench correctly medium, refrigerative ability satisfies craft requirement; Rolled steel has conditioning treatment by the requirement; (4) the impact that considers random factor, after rolled steel heat treatment, actual hardness and temperature and computational earning count temper be patient of the error of 5% . CNC Milling