The whole process of heavy gear processing shall strictly control the quality and make tracking records, and must be tested and inspected after completion. Relevant standardsT:
(1) The surface hardness of gear teeth reaches HRC 59 ～ 62 or HV 670 ～ 750;
(2) Metallographic examination The carburized layer shall be composed of tempered martensite and residual austenite, with the content of residual austenite ≤ 20% and no network carbide;
(3) The central carbon content is 0.28%~0.35%;
(4) The tooth surface shall be free of crack, indentation, scratch, pitting, burn and other defects;
(5) Ultrasonic flaw detection and magnetic particle flaw detection shall be carried out according to SEP 1921. The workpiece shall be demagnetized after gear grinding and magnetic particle flaw detection;
(6) The special heavy gear lapping test bench is used for lapping detection, and the contact area is ≥ 80%;
(7) Three coordinate measuring machine and heavy gear measuring machine are used to spot check the same products of each batch, measure various parameters and check that they are correct.
Heavy gears can be used for assembly only after passing the inspection.