Fire Safety Journal最新文献_第6页

Characteristic Compartment Fire Behaviour — A theoretical study encompassing a broader range of regimes 特征隔间火灾行为-一个理论研究，包括更广泛的制度

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-10 DOI: 10.1016/j.firesaf.2025.104589

A.H. Majdalani , I. Calderón , W. Jahn , J.L. Torero

Scaling analysis is used to characterise a series of ten different possible compartment fire scenarios as a function of compartment geometry and ventilation. In addition to the classic scenarios corresponding to Regime I and Regime II fires, eight additional cases were analysed showing that the flow characteristics are generally a function only of the Froude and Euler non-dimensional parameters. All ten scenarios can be described or bounded by the two classic and limiting regimes of behaviour, nevertheless five intermediate scenarios require spatial resolution to achieve a precise characterisation. Therefore, simple scaling analysis appears sufficient to deliver an adequate assessment of all parameters needed to define the heat transfer from the fire to the compartment until burnout of the available combustible compartment contents. The present analysis highlights the specific areas where spatial resolution is required and the potential limitations associated to the use of more detailed tools, such as CFD, for quantification in these specific areas.

尺度分析用于描述一系列十种不同的可能的隔间火灾场景，作为隔间几何形状和通风的函数。除了对应于状态I和状态II火灾的经典场景外，还分析了另外8个案例，表明流动特性通常仅是Froude和Euler无量纲参数的函数。所有十种情景都可以用两种经典和限制的行为模式来描述或限定，然而，五种中间情景需要空间分辨率来实现精确的特征描述。因此，简单的尺度分析似乎足以提供所需的所有参数的充分评估，以确定从火到隔间的热量传递，直到可用的可燃隔间内容物燃尽。目前的分析强调了需要空间分辨率的特定领域，以及在这些特定领域使用更详细的工具（如CFD）进行量化的潜在限制。

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引用次数: 0

Ignition time and heat release rate in upward flame spread: From bench to intermediate scale 向上火焰蔓延时的点火时间和放热率：从工作台到中间尺度

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-10 DOI: 10.1016/j.firesaf.2025.104566

Waseem Hittini , David Lange , Juan P. Hidalgo , Felix Wiesner

This research assesses the effect of two common assumptions in simplified flame spread models: (i) that the pyrolysis front propagates in one dimension and (ii) that ignition time (

t_{ign}

) and heat release rate per unit area (HRRPUA) values measured at bench scale can be utilised in simplified flame spread models. To that aim, the study introduces a methodology to measure time to ignition, time-dependent burning area, heat release rate per unit area, and ignition temperature for concurrent upward flame spread at intermediate-scale, while examining the feasibility of using these metrics to predict flame spread scenarios. The methodology employs a narrow-spectrum illumination source and thermocouple arrays to precisely track the pyrolysis front progression during flame spread experiment. Measurements were obtained for Poly(methyl methacrylate), and they can serve as reference points for researchers aiming to develop or refine testing protocols or perform sensitivity analyses for assumptions relevant to time to ignition and heat release rate models. Measurements were compared with cone calorimeter data from standard and modified testing protocols in the literature. Post-ignition removal of external heating reduced HRRPUA values, aligning them more closely with intermediate-scale experiments, while spatial heat flux distribution changed the time to ignition towards the values that were measured in intermediate-scale. The impact of the solid ignition parameters on the flame spread rate was evaluated individually using a simplified flame spread model. The proposed methodology provides a means to refine extrapolation methods for solid ignition parameters.

本研究评估了简化火焰传播模型中两个常见假设的影响：(i)热解锋面在一维上传播；（ii）在台架尺度上测量的点火时间（tin）和单位面积放热率（HRRPUA）值可用于简化火焰传播模型。为此，该研究引入了一种方法来测量点火时间、随时间变化的燃烧面积、单位面积的放热率以及在中等规模下同步向上火焰蔓延的点火温度，同时检查使用这些指标预测火焰蔓延情景的可行性。该方法采用窄谱照明光源和热电偶阵列来精确跟踪火焰蔓延实验过程中的热解前沿进程。获得了聚（甲基丙烯酸甲酯）的测量值，它们可以作为研究人员的参考点，旨在开发或完善测试方案，或对点火时间和热释放率模型相关的假设进行敏感性分析。测量结果与文献中来自标准和修改的测试方案的锥量热计数据进行比较。点火后去除外部加热降低了HRRPUA值，使其与中尺度实验更接近，而空间热通量分布使点火时间向中尺度实验值靠拢。采用简化的火焰传播模型，分别评价了固体点火参数对火焰传播速率的影响。提出的方法为固体点火参数的外推方法提供了一种改进方法。

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引用次数: 0

Understanding the role of buoyancy and inertia in wind-aided vegetative fires 了解浮力和惯性在风助植物火灾中的作用

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-08 DOI: 10.1016/j.firesaf.2025.104588

Abhinandan Singh , Juan Cuevas , Reza Ziazi , Pedro Reszka , Albert Simeoni

The combined effects of buoyancy and inertia forces are studied for wind-aided vegetative fires. Two fuels - Pinus palustris (PP) and Pinus rigida (PR) are tested at five different wind conditions. The flame geometrical parameters are normalized using the flame height and scaled against the inverse of the Froude number (

Fr

). A power-law relationship is observed between all the flame geometrical parameters and

1 / Fr

. The instantaneous rate of spread is calculated using an image analysis algorithm by separating flame impingement and flame spread. The behavior of the average rate of spread is explored by evaluating radiative heat flux in the preheating region. The fluctuating rate of spread (

R^{'}

) is calculated from the instantaneous and average rate of spread values. The spectral analysis of

R^{'}

shows a range of frequencies that are an integer multiple (or harmonics) of the characteristic frequency for a given experiment. Strouhal number (St) evaluated using the characteristic frequency multiplied by the leaf area index of the pine needle bed shows a linear behavior against

1 / Fr

.

研究了风助植物火灾中浮力和惯性力的联合作用。两种燃料——palustris Pinus （PP）和Pinus rigida （PR）在五种不同的风力条件下进行了测试。火焰几何参数使用火焰高度归一化，并根据弗劳德数（Fr）的倒数进行缩放。火焰几何参数与1/Fr呈幂律关系。通过分离火焰撞击和火焰蔓延，采用图像分析算法计算瞬时传播速率。通过估算预热区的辐射热流密度，探讨了平均扩散率的变化规律。从差值的瞬时速率和平均速率计算差值的波动速率（R '）。R '的频谱分析显示了一个频率范围，它是给定实验的特征频率的整数倍（或谐波）。用特征频率乘以松针床叶面积指数计算的斯特劳哈尔数（St）与1/Fr呈线性关系。

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引用次数: 0

Preventing fire-induced brittle collapse of steel tubular space trusses for reliable early warning: From mechanisms to design strategy 防止钢管空间桁架火灾脆性倒塌的可靠预警：从机理到设计策略

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-07 DOI: 10.1016/j.firesaf.2025.104586

Jinyu Li , Shaojun Zhu , Guo-Qiang Li , Yongchang Wang

Steel tubular space truss structures are widely utilized in large-space buildings but are highly susceptible to collapse under fire conditions, posing a threat to firefighters. This study conducts extensive parametric analyses to understand all fire-induced collapse modes and mechanisms of steel tubular space trusses. There are four collapse modes, of which three are categorized as ductile and one is classified as brittle due to buckling of the web members in compression. Under the brittle collapse mode, it is difficult to reliably predict the collapse of the structure for real-time early warning. This paper recommends the elimination of this failure mode in all likely fire scenarios. A design strategy is proposed to ensure that the brittle buckling failure mode of web members does not happen before that of the adjacent members in tension, whose failure is ductile. Besides, the available escape time after the early warning level is issued can be changed by adjusting the critical temperatures of the compression web members. Numerical examples demonstrate that the available escape time can increase from 0 s to over 2 min, which increases the escape time for firefighters in large-span steel structures.

钢管空间桁架结构广泛应用于大空间建筑，但在火灾条件下极易倒塌，对消防人员构成威胁。本研究进行了广泛的参数分析，以了解钢管空间桁架的所有火灾倒塌模式和机制。有四种破坏模式，其中三种为延性破坏模式，一种为脆性破坏模式，这是由于腹板在压缩下的屈曲造成的。在脆性破坏模式下，很难对结构的破坏进行可靠的预测和实时预警。本文建议在所有可能的火灾场景中消除这种故障模式。提出了一种保证腹板构件脆性屈曲破坏模式不先于相邻构件脆性屈曲破坏模式发生的设计策略。通过调整压缩腹板构件的临界温度，可以改变预警级别发布后的有效逃生时间。数值算例表明，在大跨度钢结构中，有效逃生时间由0 s增加到2 min以上，增加了消防员的逃生时间。

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引用次数: 0

Towards modeling tree-to-tree fire spread in wildland urban-interface (WUI) fires 林地城市界面（WUI）火灾中树对树的火灾传播模型研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-07 DOI: 10.1016/j.firesaf.2025.104550

Jorge Valdivia, Xiuqi Xi, Albert Simeoni, James L. Urban

Wildfires in the Wildland-Urban Interface (WUI) have intensified in recent years due to climate change and continued development of communities at the WUI. Defensible space–reducing vegetation near structures–is a mitigation strategy, but its performance under wind-driven fire conditions remains unclear. This study integrates controlled experiments with Fire Dynamics Simulator (FDS) modeling to investigate ignition between trees subjected to wind-aided flame spread. A custom-designed propane burner, representing fire exposure similar to a 2 MW tree fire, exposed downwind Douglas-fir trees under flow velocities of 1.0 and 2.0 m s⁻¹, across varying separation distances. Total and radiative heat fluxes were measured using water-cooled gauges, and ignition behavior was evaluated through logistic regression. Flame impingement emerged as the dominant ignition mechanism, with convection significantly increasing heat transfer to downwind trees at short separation distances. Simulations reproduced key trends in heat flux and flame geometry but over-predicted radiation and under-predicted convection, especially at short separations. Critical ignition distances increased with wind speed, highlighting the role of wind-driven flame elongation and the need for flow-aware defensible space recommendations. The experiments provide insight into the use of computational fire modeling to inform defensible space guidelines tailored to specific environmental and fire conditions.

近年来，由于气候变化和城市交界面社区的持续发展，城市交界面地区的野火愈演愈烈。可防御的空间——减少建筑物附近的植被——是一种缓解策略，但它在风力驱动的火灾条件下的表现仍不清楚。本研究将对照实验与火焰动力学模拟器（FDS）模型相结合，研究了风助火焰传播下树木之间的点火情况。一个定制设计的丙烷燃烧器，代表了类似于2兆瓦树木火灾的火灾暴露，在1.0和2.0 m s- 1的流速下，在不同的分离距离上暴露下风道格拉斯冷杉树。用水冷计测量总热流和辐射热通量，并通过逻辑回归评估点火行为。火焰碰撞是主要的点火机制，对流显著增加了短间隔距离下风向树木的传热。模拟再现了热通量和火焰几何形状的关键趋势，但高估了辐射，而低估了对流，特别是在短间隔时。临界点火距离随着风速的增加而增加，这突出了风驱动火焰延伸的作用，以及对流动感知防御空间建议的需求。这些实验提供了对使用计算火灾模型的洞察力，以告知针对特定环境和火灾条件量身定制的防御空间指南。

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引用次数: 0

A novel fire hazard evaluation method for cable sheaths under various ageing conditions 不同老化条件下电缆护套火灾危险性评估新方法

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-05 DOI: 10.1016/j.firesaf.2025.104572

Hui Liu, Wenqiang Wang, Long Yan, Zhisheng Xu

Fire hazard is one of the most serious security threats to the service cable under different environmental conditions, and comprehensive evaluation is critical for fire safety. A novel evaluation method of fire hazard for cable sheaths after various ageing treatment was established based on entropy weight method (EWM), analytic hierarchy process (AHP), grey relational analysis (GRA), and technique for order preference by similarity to an ideal solution (TOPSIS) method. By analyzing factors that leaded to fire accidents, 15 evaluation indicators were determined from three aspects, including ignition, heat and smoke hazards. Combined with the characteristics of each evaluation method, the AHP-EWM method was used to obtain combination weight values, and the comprehensive evaluations for the fire hazards of the sheaths under different ageing conditions were realized by the TOPSIS-GRA method. The results show that the heat hazard of low-smoke halogen-free sheath is higher, while the smoke hazard of PVC sheath is larger. Simultaneously, the negative impact of hygrothermal condition is the most significant, succeeded by the salt spray condition, while the weaken effect of thermal condition is the smallest. In contrast to the traditional evaluation method of fire hazards, the evaluation results from the TOPSIS-GRA method are more accurate and reliable.

火灾是不同环境条件下服务电缆最严重的安全威胁之一，综合评价是保障服务电缆防火安全的关键。基于熵权法（EWM）、层次分析法（AHP）、灰色关联分析法（GRA）和理想解相似性排序偏好法（TOPSIS），建立了不同老化处理后电缆护套火灾危险性评价方法。通过分析导致火灾事故的因素，从着火、热和烟雾危害三个方面确定了15个评价指标。结合各评价方法的特点，采用AHP-EWM法获得组合权重值，采用TOPSIS-GRA法实现对不同老化条件下护套火灾危险性的综合评价。结果表明，低烟无卤护套的热危险性较高，而PVC护套的烟危险性较大。同时，湿热条件的负面影响最为显著，其次是盐雾条件，而热条件的弱化作用最小。与传统的火灾危险性评价方法相比，TOPSIS-GRA方法的评价结果更加准确可靠。

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引用次数: 0

Reappraisal of Jin's visibility through fire smoke experiment: Insights into signage visibility and the impact of ambient light 通过火烟实验重新评价Jin的可见度：对标识可见度和环境光影响的洞察

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-05 DOI: 10.1016/j.firesaf.2025.104573

Wai Kit Cheung , Jakub Bielawski , Lukas Arnold , Xinyan Huang , Wojciech Węgrzyński

Jin's experiments in the 1970s contributed to fire evacuation research, but only examined relatively high ambient light levels. By replicating the Jin's experimental setup and varying ambient light level, we explore the relationship between smoke extinction coefficient, background illumination and signage emitting light intensity under low-light real-world emergency scenarios. Firstly, we confirm Jin's observation of a linear relationship between smoke extinction coefficient (

σ

) and visibility distance (

V

), although our measurements of

σ

are 7–11 % higher under equivalent signage luminance. Our findings on the

σ

versus normalized brightness

π L_{t} / E

at a 15.5 m distance align with Jin's results, while a 20 % discrepancy is observed at 10.5 m and 5.5 m distances. At high ambient light (180 lx), the

K = σ V

is comparable in Jin's experiment (from 5 to 8) and this work (from 4.7 to 9.5). However, at low ambient light (less than 22 lx), the signage remains visible in higher smoke extinction coefficients (with K from 6 to 11). The critical extinction coefficient decreases by nearly 40 % for every 5 m increase in visibility distance. This work deepens the understanding of smoke visibility under a dark fire environment, which may help guide fire signage design and inspire new fire evacuation research.

金在20世纪70年代的实验为火灾疏散研究做出了贡献，但只检查了相对较高的环境光水平。通过复制Jin的实验装置和不同的环境光水平，我们探索了在低光的现实世界紧急情况下，烟雾消光系数、背景照度和标牌发光强度之间的关系。首先，我们证实了Jin对烟雾消光系数（σ）和可见距离(V)之间的线性关系的观察，尽管在等效标识亮度下我们的σ测量值高出7 - 11%。我们在15.5 m距离处的σ与归一化亮度πLt/E的结果与Jin的结果一致，而在10.5 m和5.5 m距离处观察到20%的差异。在高环境光（180 lx）下，K=σV在Jin的实验（从5到8）和本工作（从4.7到9.5）中是相当的。然而，在低环境光（小于22 lx）下，标识在较高的烟雾消光系数（K从6到11）下仍然可见。能见度每增加5 m，临界消光系数降低近40%。本研究加深了对暗火环境下烟雾可见度的认识，有助于指导防火标识设计，启发新的火灾疏散研究。

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引用次数: 0

Impact of high-concentration smoke aerosols on radar electromagnetic wave propagation in building fire 高浓度烟雾气溶胶对建筑火灾中雷达电磁波传播的影响

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-03 DOI: 10.1016/j.firesaf.2025.104568

Song Wang , Jing Geng , Wenguo Weng

This study investigates the impact of high-concentration smoke aerosols on radar electromagnetic wave propagation in building fire scenarios. A computational model based on Mie scattering theory and existing databases was developed to evaluate the influence of smoke aerosols on radar signals. Additionally, a voxel-based Finite-Difference Time-Domain (FDTD) simulation method was designed to model complex random media, and simulations were conducted to validate the computational model. An experimental platform was also constructed to assess the impact of high-concentration smoke on radar electromagnetic waves, utilizing three types of radars: NVA-R641, X4M03, and IWR6843. Data collected under typical smoke conditions revealed attenuation coefficients of approximately 0.03 dB/m at 2.95 GHz, 0.37 dB/m at 8.75 GHz, and 0.76 dB/m at 60 GHz. These results support the theoretical model and demonstrate the feasibility of the simulation approach. This research provides a comprehensive framework for understanding and predicting the effects of high-concentration smoke aerosols on radar systems in building fire scenarios, offering valuable tools for optimizing radar performance and enhancing the reliability of life-saving operations in smoke-filled environments.

研究了建筑火灾场景下高浓度烟雾气溶胶对雷达电磁波传播的影响。基于Mie散射理论和现有数据库，建立了烟雾气溶胶对雷达信号影响的计算模型。此外，设计了一种基于体素的时域有限差分（FDTD）模拟方法来模拟复杂随机介质，并进行了仿真验证。利用NVA-R641、X4M03和IWR6843三种型号的雷达，搭建了一个实验平台来评估高浓度烟雾对雷达电磁波的影响。在典型烟雾条件下收集的数据显示，衰减系数在2.95 GHz时约为0.03 dB/m，在8.75 GHz时约为0.37 dB/m，在60 GHz时约为0.76 dB/m。这些结果支持了理论模型，并证明了仿真方法的可行性。本研究为理解和预测建筑火灾场景中高浓度烟雾气溶胶对雷达系统的影响提供了一个全面的框架，为优化雷达性能和提高烟雾弥漫环境中救生操作的可靠性提供了有价值的工具。

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引用次数: 0

Experimental investigation of cellular steel beams at ambient and elevated temperatures 室温和高温条件下蜂窝钢梁的试验研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-03 DOI: 10.1016/j.firesaf.2025.104574

Luana V. da Silva , Nickolas Giacomitti , Débora Ferreira , Nuno Lopes , Luís M.R. Mesquita

Cellular steel beams, commonly used in modern construction, exhibit complex failure mechanisms that have not been thoroughly explored, especially under fire conditions. This research investigates the structural behaviour of cellular beams under both ambient and elevated temperatures, with a focus on load-bearing capacity and failure modes. Experimental tests were conducted on a solid beam and six cellular beams with varying hole spacings and diameters at different temperatures. All beams were tested under three-point bending, subjecting the openings and the web posts to different combinations of bending moments and shear forces. Experimental maximum loads and failure modes are compared with the design method of EN1993-1-13 and EN1993-1-2. At ambient temperature, failure modes varied with beam design: specimens with smaller opening spacings failed by web-post buckling, while larger openings resulted in a Vierendeel mechanism. While the Eurocode predictions for load capacity were conservative under ambient conditions, the design model did not accurately predict the correct failure mode. Elevated temperatures significantly reduced the load capacity and, in some cases, changed the collapse mechanism. These results highlight that current design rules are unreliable in predicting the failure mode and may not ensure safety at higher temperatures, stressing the need for specific design rules for cellular beams in fire conditions.

在现代建筑中广泛使用的蜂窝钢梁，其复杂的破坏机制尚未得到充分的研究，特别是在火灾条件下。本研究调查了蜂窝梁在环境和高温下的结构行为，重点关注承重能力和破坏模式。在不同温度下，对一根实心梁和6根孔间距和直径不同的蜂窝梁进行了实验测试。所有梁都在三点弯曲下进行了测试，使开口和腹板柱受到不同的弯矩和剪力组合。将试验最大载荷和破坏模式与EN1993-1-13和EN1993-1-2的设计方法进行了比较。在环境温度下，梁的破坏模式因梁的设计而异：开口较小的试件因网柱屈曲而破坏，而开口较大的试件则因Vierendeel机制而破坏。虽然欧洲规范对环境条件下负荷能力的预测是保守的，但设计模型不能准确预测正确的失效模式。高温显著降低了承载能力，在某些情况下，还改变了坍塌机制。这些结果强调，目前的设计规则在预测失效模式方面是不可靠的，并且可能无法确保高温下的安全，强调需要针对火灾条件下的蜂窝梁制定特定的设计规则。

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引用次数: 0

Experimental investigation on mechanical properties of cast steel at elevated temperatures 铸钢高温力学性能的试验研究

IF 3.3 3区工程技术 Q2 ENGINEERING, CIVIL

Fire Safety Journal

Pub Date : 2025-11-01 DOI: 10.1016/j.firesaf.2025.104571

Hongbo Liu , Bingxu Han , Liulu Guo , Zhihua Chen

Cast steel is extensively used in diverse building structures, especially for complex joints and members. To guarantee the safety of cast steel components during fire events, precise characterization of mechanical properties and constitutive behavior of cast steel at elevated temperatures is imperative. This study presents a comprehensive experimental investigation of G20Mn5N and G20Mn5QT cast steels. Key mechanical property indexes of cast steel at elevated temperatures were determined and compared to code-specified values and high-temperature data for conventional structural steels. Results indicate that the cast steels exhibited a blue brittleness phenomenon at 300 °C, characterized by increased ultimate strength and reduced toughness and ductility, ultimately predisposing them to brittle failure. Cast steel exhibited pronounced thermochromic behavior and ductile damage characteristics at elevated temperatures. With increasing temperature, the modulus of elasticity, yield strength, and ultimate strength of cast steel decreased, while elongation initially diminished before increasing. G20Mn5QT demonstrated superior fire resistance compared to G20Mn5N. Highly accurate empirical prediction equations for critical mechanical properties and theoretical stress-strain formulas at elevated temperatures were developed.

铸钢广泛应用于各种建筑结构，特别是复杂的接缝和构件。为了保证铸钢构件在火灾中的安全，精确表征铸钢在高温下的力学性能和本构行为是必不可少的。本文对G20Mn5N和G20Mn5QT铸钢进行了综合试验研究。测定了铸钢在高温下的关键力学性能指标，并与规范规定的数值和常规结构钢的高温数据进行了比较。结果表明，铸钢在300℃时表现出蓝色脆性现象，其特征是极限强度增加，韧性和延展性降低，最终导致脆性破坏。铸钢在高温下表现出明显的热致变色行为和延展性损伤特征。随着温度的升高，铸钢的弹性模量、屈服强度和极限强度下降，伸长率先降低后升高。与G20Mn5N相比，G20Mn5QT表现出更好的耐火性。建立了高精度的临界力学性能经验预测方程和高温下的应力-应变理论公式。

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引用次数: 0