HOT TENSILE PROPERTIES OF SIMULATED HEAT-AFFECTED ZONE MICROSTRUCTURES OF 9CR-1MO WELDMENT

被引：33

作者：

LAHA, K

CHANDRAVATHI, KS

RAO, KBS

MANNAN, SL

机构：

[1] Indira Gandhi Centre for Atomic Research, Kalpakkam

来源：

INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING | 1995年 / 62卷 / 03期

关键词：

D O I：

10.1016/0308-0161(94)00023-C

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The heat-affected zones (HAZ) of 9Cr-1Mo steel weldments consist of coarse-grain martensite with delta-ferrite, coarse-grain martensite, fine-grain martensite and intercritical structure. These HAZ microstructures have been simulated with respect to microstructure, hardness and grain size by isothermal heat treatment cycles in the temperature range 973-1573 K. Tensile tests at a strain rate of 3 x 10(-4) s(-1) over the range 298-873 K showed that 0.2% YS and UTS values for the various microstructural conditions were in the descending order of coarse-grain martensite, coarse-grain martensite with delta-ferrite, fine-grain martensite, base metal and intercritical structure. The presence of delta-ferrite in the coarse-grain region of HAZ restricted the grain growth, the increase in strength and the decrease in ductility. This minimises the problem of cracking in the coarse-grain region of HAZ in this steel which is often encountered in low-alloy Cr-Mo ferritic steels. The regions with intercritical structure showed the lowest strength and fracture energy. Fine-grain martensite exhibited a good combination of strength and ductility in the HAZ.

引用

页码：303 / 311

页数：9

共 20 条

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