The effects of precool-quenching temperature(450～1100 ℃) on martensite transformation starting temperature Ms of T91 ferritic heat-resistant steels were studied by DIL805A/D high-resolution differential dilatometer.

Based on that hardened case depth can be increased by delay in air after forging,the technique of delay quenching after forging is proposed in this paper.

Effects of Si and Austempering on the Wearresistance Property of ZG30SiMnCr;

Effect of Austempering on Mechanical Properties and Abrasion-Resistance of Mn -Cr Alloyed White Cast Iron;

Research of austempering process of low-carbon ductile iron;

Strengthening and Toughening of Die Steel Cr7Mo3V2Si by Isothermal Hardening with Prenitriding and Diffusion;

The influences of various isothermal hardening treatments on microstructure and properties of semi-steel made by quenching and isothermal hardening and forging,which contain 1.

2)=900～1000 MPa,σ_b=1300～1564 MPa)and excellence plasticity(δ_5=15%～18%)were obtained after aus- tenitization at 840～880℃followed by isothermal hardening for 3 hours.

The influence of austempering treatment on the microstructure, retained austenite and fracture toughness of high silicon cast steel has been studied.

The results show that a pure ausferrite structure that consists of bainitic ferrite and carbon riched retained austenite can be obtained by austempering treatment of high silicon cast steel over a large temperature range (240～400℃).