高强度低合金钢(HSLA)的研究进展

Research Development of High Strength Low Alloy( HSLA) Steels

高强度低合金钢是在普通碳素钢基础上发展起来的,由于其强度适中、加工性好且经济适用而在汽车、船舶与海洋工程以及桥梁等基础设施建设方面得到了广泛的应用。由于对钢材性能要求的不断提高,尤其是焊接性能和低温韧性,因此铜沉淀强化高强度低合金钢受到极大的重视而迅速发展起来。首先介绍了高强度低合金钢的发展历程,结合强化机制重点介绍了双相高强度低合金钢和含铜高强度低合金钢的开发思想,并对高强度低合金钢的基体相显微结构控制和强化方式进行了评述;随后对等温冷却和连续冷却过程中高强度低合金钢的相变尤其是铜沉淀相的析出过程进行了介绍;最后介绍了富铜纳米相的概念以及表征纳米相的方法,评述了合金元素对富铜纳米相形成的影响。

High strength low alloy （HSLA） steels were developed based on the plain carbon steels. HSLA steels have been applied widely to automobile industry, ship building and marine engineering, and infrastructure construction, etc., due to the moderate mechanical properties, good formability and low cost. With the requirement in the improved properties of steels, specifically weldability and low-temperature toughness, HSLA steels were strengthened by Cu-pre- cipitation, which have attracted great interest. In this paper, the origin of HSLA steels was introduced firstly, combi- ning with the discussion of the strengthening mechanisms. The emphasis was mainly placed on the dual-phase HSLA steels and Cu-precipitation strengthened HSLA steels. The control of steel matrix microstructure and their effects on the mechanical properties were reviewed. Subsequently, phase transformation of matrix and Cu precipitation processes dur- ing both isothermal cooling and continuous cooling were reviewed. Finally, the concept of Cu-rich nanoclusters in HSLA and the corresponding advanced characterization methods were introduced. The effects of alloying elements on the forma- tion of Cu-rich nanoclusters were also reviewed.