Scholarlink

<p>The influence of heat input on heat-affected zone (HAZ) degradation and structural performance of thermo-mechanically controlled processed (TMCP) high-strength low-alloy (HSLA) steels remains insufficiently understood, particularly in welded square hollow section (SHS) connections. This study investigates the static bending behavior of gas metal arc welded (GMAW) SHS column-to-beam connections manufactured from Strenx®700MC steel. Undermatching (AWS ER80S-G) and overmatching (AWS ER120S-G) filler metal were employed, and twelve full-scale joints were produced using heat inputs ranging from 0.3 to 1.6&#xa0;kJ/mm. Experimental bending tests, hardness measurements, analytical calculations, finite element simulations, and two-way analysis of variance (ANOVA) were used to evaluate the effects of heat input and filler metal strength on joint performance. Increasing heat input initially improved bending resistance by enhancing weld penetration and effective weld area. However, excessive heat input promoted thermal-cycle-induced HAZ softening, leading to strain localization and reduced load-carrying capacity. An optimal heat input of approximately 1.2&#xa0;kJ/mm was identified. Although the overmatching filler metal increased nominal weld metal (WM) tensile strength by approximately 44%, the ultimate bending load increased by only 3%, demonstrating a limited structural benefit. Finite element analyses indicated that the highest stress and strain concentrations occurred at the weld toe and adjacent regions where failure initiation was experimentally observed, while two-way ANOVA confirmed that heat input was the dominant factor governing HAZ hardness. The results demonstrate that controlling welding thermal cycles is more effective than increasing filler metal strength for improving the bending performance of welded SHS connections manufactured from TMCP high-strength steels.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Effect of heat input and filler metal strength on the HAZ softening and static bending behavior of GMAW-welded connections in Strenx®700MC high-strength steel

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月6日

查看全文
  • Rafael Luciano Dalcin,
  • Ivan Guerra Machado,
  • João Ricardo Boff Preichardt,
  • Andryéli da Silva Soares,
  • Victor Velho de Castro,
  • Cristiano José Scheuer,
  • Richard Thomas Lermen,
  • Luis Fernando Nicolini

摘要

The influence of heat input on heat-affected zone (HAZ) degradation and structural performance of thermo-mechanically controlled processed (TMCP) high-strength low-alloy (HSLA) steels remains insufficiently understood, particularly in welded square hollow section (SHS) connections. This study investigates the static bending behavior of gas metal arc welded (GMAW) SHS column-to-beam connections manufactured from Strenx®700MC steel. Undermatching (AWS ER80S-G) and overmatching (AWS ER120S-G) filler metal were employed, and twelve full-scale joints were produced using heat inputs ranging from 0.3 to 1.6 kJ/mm. Experimental bending tests, hardness measurements, analytical calculations, finite element simulations, and two-way analysis of variance (ANOVA) were used to evaluate the effects of heat input and filler metal strength on joint performance. Increasing heat input initially improved bending resistance by enhancing weld penetration and effective weld area. However, excessive heat input promoted thermal-cycle-induced HAZ softening, leading to strain localization and reduced load-carrying capacity. An optimal heat input of approximately 1.2 kJ/mm was identified. Although the overmatching filler metal increased nominal weld metal (WM) tensile strength by approximately 44%, the ultimate bending load increased by only 3%, demonstrating a limited structural benefit. Finite element analyses indicated that the highest stress and strain concentrations occurred at the weld toe and adjacent regions where failure initiation was experimentally observed, while two-way ANOVA confirmed that heat input was the dominant factor governing HAZ hardness. The results demonstrate that controlling welding thermal cycles is more effective than increasing filler metal strength for improving the bending performance of welded SHS connections manufactured from TMCP high-strength steels.

Graphical Abstract