Detail of QC/T 276-1999

Introduction of QC/T 276-1999

Specifications for heat treatment hardness of automobile parts 1 Subject content and application scope This standard specifies the specifications for heat treatment hardness of automobile parts. This standard is applicable to the final heat treatment of automobile parts. 2 Heat treatment hardness of common materials for automobile parts as specified in Table 1 Table 1 Heat treatment Process Material Hardness specifications Application examples HB HRC HV Carburization 08 and 20 50~55 58~63 Valve tappet, camshaft, piston pin, washer, baffle, etc. 15Cr, 20Cr, 20Mn, 20CrMnTi, 20CrMn, 20CrNiMo, 12CrNi3, 20CrNi3, 20MnVB, 20Mn2TiB, 20CrMnMo and 20CrMo 58~63 Camshaft, piston pin, starting gear, steering nut, ball pin, rocker shaft, leaf spring pin, universal joint, universal joint pin, etc. (Soft) nitridation 40 and 45 400~600 600~800 Odometer gear, timing gear and oil pump transmission gear HT 200, HY 250 and HT 350 400~600 600~800 Timing gear and oil pump transmission gear 38CrMoAl and Cr12MoV 800~1,000 Carbonitriding B2F and B3 08, 10, 15, 20, Y12 and Y15 40~45 48~53 53~58 58~63 ≥500 Clutch driven plate, hand-operated toothed plate, transmission fork, carburetor rocker arm, rocker shaft, steering lever ball seat, hand-operated shoe bracing plate, ball pin seat, extra-thick nut, spherical strut, etc. ML10, ML15, ML20 and ML35 43~48 48~53 53~58 58~63 Worm, screw, bolt, pump diaphragm ejector rod and adjusting mechanism body 35 and 40 35~40 40~45 ≥650 Locating pin, washer, driven disc, etc. 15Cr, 20Cr, 20CrMnTi and 12Cr2Ni4A 48~53 53~58 58~63 Rocker shaft, valve tappet, worm and gear sleeve 40Cr and 40MnB 53~58 58~63 ≥650 Steering worm and locating pin Induction quenching Normalized state 25, carburized part 25, 40 and 45 40~48 48~56 56~63 Door latch, swing arm shaft, camshaft, transmission fork shaft, crankshaft, etc. ZG 310-570, HT 200, HT 150, QT 600-2 and QT 900-5 48~53 53~58 58~63 Release yoke, separate bearing sleeve, gear shaft, transmission shaft flange, crankshaft, etc. Quenched and tempered state 35, 40 and 45 48~53 53~58 58~63 Master gear flange plate, ball pin seat, gear shaft, transmission shaft, etc. 40Cr and 40MnB 48~53 53~58 58~63 Spline shaft, crankshaft, gear shaft, transmission shaft flange, camshaft, etc. 30CrMo, 35CrMo, 30CrMoSiA, 42CrMo, 35CrMnSiA and 40CrMnMo 48~53 53~58 58~63 Flywheel ring gear, steering knuckle, crankshaft, half shaft, etc. Quenching and tempering 35, 40, 45, 50, ML35, ML45, ZG 270-500 and ZG 310-570 207~241 255~285 285~321 341~415 30~35 35~40 40~45 45~50 Clutch driven disc hub, locking nut, fastening bolt, threaded fork, locating pin, hand-operated shoe rocker arm and slack adjuster arm 15, 20, 15MnVB, 16Mn, 15Cr and 20Cr 35~42 42~48 48~55 55~63 Thrust ring, washer, bolt and wedge-shaped lock pin 35CR, 40Cr, 45Cr, ML40Cr, 40CrMnMo and 40CrNiMoVA 255~285 285~321 341~415 30~35 35~40 40~45 45~50 Column bolt, rear lifting lug shaft, rear axle shaft, key pin, etc. 30CrMo, 35CrMo and 42CrMo 207~241 255-285 30~35 35~40 40~45 45~50 Crankshaft and connecting rod Y40Mn, 45Mn and 45Mn2 207~241 255~285 33~38 38~42 42~48 Bolt, pin, torsion bar, half shaft sleeve, etc. 40MnB and 45MnB 255~285 285~312 30~35 35~40 Screw 85 52~58 Valve block 65Mn 37~42 42~48 48~53 Push rod joint ball collar, elastic collar, leaf spring, valve spring, valve block, etc. 55Si2Mn, 60Si2Mn and 55SiMnVB 42~48 Spring steel wire, plate spring, etc Normalizing 35, 40, 45, 35Cr, 40Cr, 40MnB and 40CrMnMo 197~241 241~285 Crankshaft 45Mn2 207~285 QT 600-2, QT 700-2 and QT 900-5 240~321 Crankshaft Notes: ① The harness specified in the table refers to the surface hardness of the parts, and the core hardness shall meet those specified in the relevant technical documents. ② In order to facilitate inspection, the hardness value in a certain unit may be converted to that in another unit, provided that it meet the inspection rules of relevant standards.

Contents of QC/T 276-1999

1 Subject content and application scope 2 Heat treatment hardness of common materials for automobile parts as specified in Table Additional explanation