2017 Bessemer lecture: progress in steel product research to advance the industry and society*

Steel development has been ongoing for generations and has enabled steel to play an important role in modern society. We might consider that metallurgists are often unsung heroes of this progress where product and process development have enabled technological progress, and steel developments are occurring faster than ever in some areas today. Last year’s Bessemer lecture links the speaker’s background with Bessemer Award history, and celebrates some of the heroes of steel product development that have impacted him, and have also impacted society and the development of the steel industry.     

The high-speed deformation behavior of TRIP steels

The high-speed deformation behavior of TRIP steel was investigated at strain rates ranging from 10⁻² s⁻¹ to 10³ s⁻¹. The effects of metallurgical factors, such as the rolling direction, thickness, and gage length, on the tensile properties at various strain rates were evaluated. The ultimate tensile strength, uniform elongation, strain rate sensitivity, absorbed energy, and strain-hardening exponent are reported. In general, the strength increases and the ductility decreases as the strain rate increases. The samples with a high amount of retained austenite had two distinct regions of strain rate sensitivity, showing high strain rate sensitivity over a strain rate of 10² s⁻¹. The tensile properties were not affected by the gage length and thickness of the tensile samples; however, the rolling direction of the tensile samples affected the UTS values slightly. The absorbed energy of the TRIP steel greatly exceeded that of HSLA steel.     

Is the dissociability of working memory systems for name identity, visual-object identity, and spatial location maintained in old age?

The dissociability of working memory for name identity (verbal information), visual objects, and spatial location was explored in 3 experiments. Consistent with previous results, the 3 working memory systems were dissociable in younger adults. Both younger and older adults showed involvement of name identity in an object identity task, and older adults showed this involvement in a spatial memory task. Results were interpreted as showing that the systems are generally separable but that involvement of 1 with another is possible and more likely in older adults. A 4th, correlational study showed that there is generalized decline in working memory systems in old age, with the age differences in memory mediated to a moderate extent by age-related differences in speed of processing. It was speculated that the specific, possibly strategic changes are independent of and take place against a backdrop of generalized loss of nervous system integrity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Q&P钢热处理工艺的开发进展

Q&P钢的工艺概念已提出了有些年了,它作为一种热处理工艺,生产的组织具有马氏体和富C的亚稳残余奥氏体.工艺包括:控制淬火形成部分的马氏体,然后热处理以使C从过饱和的马氏体中转移到残余奥氏体中.潜在的应用包括具有好的成型性和抗断裂的高强度钢.应用该工艺可生产薄板和厚板,以及用从长锻材生产热处理元件,甚至于铸铁.自2003年一直在实验室研究,早期的工作结果已有发表.近期的研究主要集中于机理方面的细节.国际范围的独立团队在此研究领域也有很多进展.     

Effect of Testing Temperature on Retained Austenite Stability of Cold Rolled CMnSi Steels Treated by Quenching and Partitioning Process

The effect of testing temperature on retained austenite (RA) stability of industrially cold rolled CMnSi sheet steel treated by quenching and partitioning (Q&P) process has been investigated by observing the deformation and transformation behavior of RA at different testing temperatures. Uniaxial tensile properties at different temperatures were determined and a correlation between RA stability and mechanical properties were also established. Ultimate tensile strength increases monotonously when temperature decreases, while total elongation reaches an optimum value between 0 and 20°C, where RA exhibits the greatest TRIP effect. Work hardening rate was calculated to decrease through three different stages in an oscillation manner, leading to significant enhancement in both strength and ductility. The kinetic of deformation‐induced martensite transformation is also studied and the stability of RA can be evaluated by comparing the kinetic parameter β.     

Five methods for computing significant individual client change and improvement rates: Support for an individual growth curve approach.

[Correction Notice: An erratum for this article was reported in Vol 70(6) of Journal of Consulting and Clinical Psychology (see record 2007-16954-001). In this article, the values reported for hierarchical linear modeling (HLM) in Table 2 (p. 1046) were incorrect. This erratum provides the correct values and further information on the conclusion of the study.] Interest has been renewed in methods for determining individual client change. Currently, there are at least 4 pretreatment–posttreatment (pre-post) difference score methods. A 5th method, based on a random effects model and multiwave data, represents a growth curve approach and was hypothesized to be more sensitive to detecting significant (p?p?     

Mechanical properties of high-Si plate steel produced by the quenching and partitioning process

The microstructures and mechanical properties of a high-Si (1.5 wt.%) steel produced by a novel process of quenching and partitioning (Q & P) were compared with those obtained using traditional heat treatments (i.e. austempering, intercritical annealing for dual phase, quench and tempering). Plate steel was included for exploration of the Q & P process in applications requiring strength and toughness (such as an API line pipe), where retained austenite may contribute to the overall toughness via the TRIP phenomenon at a crack top. The Q & P process is based on the partial transformation of austenite to martensite, followed by partitioning of carbon from martensite into austenite, which leads to an untypical microstructure. Retained austenite amounts up to 6 vol.% with a carbon content of up to 0.88 wt.% were achieved in 0.1% carbon steel using Q & P. Superior impact toughness at higher yield strength levels was found after Q & P compared to other traditional heat treatments with equivalent partitioning, austempering or tempering conditions.