首先制定了球化退火方案，以不同组试验研究不同的加热温度、保温时间对组织

Firstly, a spheroidizing annealing scheme was developed, and different groups of experiments were used to study the effects of different heating temperatures and holding times on the structure and performance. Find the structure with the best effect of carbide spheroidization, and then determine the best spheroidizing annealing scheme for the preparation of subsequent quenching. <br>Then according to the determination of the spheroidizing annealing test plan, all samples were spheroidized and annealed for quenching test, and different groups of tests were used to study the effect of different heating temperature and holding time on the structure and performance. Find the structure with the least residual austenite and carbide after quenching and the largest amount of martensite. In this way, the best quenching test plan is determined to prepare for tempering. <br>Finally, according to the determination of the quenching test plan, all samples are quenched and then subjected to the tempering test. The effects of tempering temperature, tempering time, and number of tempering on the organization and performance are mainly studied in different groups of tests. A structure with the best effect of transforming residual austenite to tempered martensite and uniform distribution of fine carbides was found. Use this to determine the final tempering plan.

Firstly, a spherical annealing scheme was developed to study the effects of different heating temperature and insulation time on tissue and performance with different groups of experiments. Find the organization that works best with carbide to determine the best spherical annealing solution to prepare for the quenching behind.<br>Then, according to the determination of the spherical annealing test scheme, the quenching test is carried out after the sample spherical deheating, and the effect of different heating temperature and insulation time on tissue and performance is studied in different groups. The tissue with the least residual Austproandandand and carbide after quenching was found, and the tissue with the largest mass of the martomac. In order to determine the best quenching test scheme to prepare for tempering.<br>Finally, according to the determination of quenching test scheme, all specimens were quenched and tempered, and the effects of tempering temperature, tempering time and tempering frequency were mainly studied in different groups. Find the tissue that residual Aumersain transforms into the best tempered, thin carbide distributed. to determine the final tempering scenario.

Firstly, the spheroidizing annealing scheme was established, and the effects of different heating temperature and holding time on the structure and properties were studied by different groups of experiments. Find out the structure with the best effect of carbide spheroidization, so as to determine the best spheroidizing annealing scheme for the preparation of the later quenching.<br>Then, according to the determination of spheroidizing annealing test plan, the quenching test is carried out on all samples after spheroidizing annealing, and the effects of different heating temperature and holding time on the structure and properties are studied by different groups of tests. The microstructure with the least retained austenite and carbide and the most martensitic content after quenching was found. In this way, the best quenching test scheme is determined to prepare for tempering.<br>Finally, according to the determination of quenching test plan, all samples were tempered after quenching, and the effects of tempering temperature, tempering time and tempering times on the structure and properties were mainly studied by different groups of tests. The microstructure with the best effect of transformation from retained austenite to tempered martensite and uniform distribution of fine carbides was found. So as to determine the final tempering plan.<br>