High-impact toughness of weld joints match is not less than the base metal heat affected zone toughness is much smaller than the base material is a joint in the heat-affected zone fracture important reasons .

高匹配接头 焊缝冲击韧性不小于母 材，热影响 区冲击韧性远小于母材，是接头在热影响区断裂的重要原因。

The results show that narrow gap SAW weld metal zone consisted of acicular ferrite ( AF ) and dispersed carbide .

结果表明： BHW35钢 焊缝 焊态时组织为针状铁素体，在晶内有细小碳化物弥散分布；

The results show that : under the no preheating condition the microstructure of weld metal is columnar austenitic and brittle martensite exists in the fusion zone and over-heated zone unavoidably .

研究结果表明：在不预热条件下，用KD286 焊 补 钢轨， 焊缝组织为柱状奥氏体组织，熔合 区和过热区不可避免地产生脆硬的马氏体组织。

The fracture toughness of the weld metal is lower than that of the base metal and the fracture toughness of heat-affected zone ( HAZ ) is intervenient between those of weld metal and base metal .

接头 焊缝 金属的断裂韧度显著低于母材，而热影响 区断裂韧度则介于母材和焊缝金属之间。

It is manifested that in single pass weld metal there are no copper precipitations but in heat affected zone there are some ε - Cu precipitations and the distribution and size of the precipitations are not uniform .

研究结果显示，单道 焊 焊缝 金属中铜难以析出，在多道焊道间热影响 区有εCu析出颗粒的存在，但析出颗粒尺寸与分布存在不均匀性。

The nature and formation mechanism of the cracks in the weld metal and heat affected zone of this reactor are researched in this paper .

本文研究了该反应器 焊缝及热影响 区出现的裂纹的性质和形成机理。

Weld metal zone are mostly acicular ferrite which can improve the weld zone toughness .

焊缝 金属 区晶粒分布均匀， 焊缝 金属 区多为针状铁素体，能够提高焊缝区的韧性。

The results showed that the low-temp toughness of weld metal could be improved markedly through the welding method of two beads per layer so that the recrystallization occurred in the middle zone of weld .

结果表明：通过采用每层两道的焊接工艺，使对接焊缝中心 部位全部发生重结晶，是 焊缝 金属低温韧性提高的关键。

This deformation twinning is generat-ed by a abruptly induced tensile stress concentration which is a result of contraction in the weld metal zone dur-ing the solidification and delta-ferrite to austenite phase transformation processes and rapid cooling .

这些形变孪晶是由于在 奥氏体 钢 焊缝冷却过程中，结晶凝固和δ－铁素体向奥氏体的相转变，导致 焊缝体积缩小而快速引入的拉伸切应力产生的。

To add Cu 、 Ni 、 Mo elements to base metal and weld metal is effective to welding zone selective corrosion .

在母材和 焊缝中添加Cu、Ni、Mo元素对焊接 区耐选择性腐蚀是有效果的。

In the uranami weld metal of combined weld the weakest zone of fracture toughness is near the bond line and is related with the structure characteristic and carbon diffusion of the dissimilar steel weld .

组合焊缝接头断裂韧性的薄弱环节在底层 焊缝中近熔合线处，异种钢焊缝熔合 区的组织特性，特别是碳的迁移，与该 区的低韧性密切相关。

The basic requirement of welding the steel 2205 is that the weld metal and heat-affected zone obtain a favorable phase balance and retain the performance as the base metal after welding .

平衡铁素体和奥氏体两相组织在 焊缝 金属和热影响 区中的比例，保证焊接接头的性能，是双相不锈钢焊接的基本要求。

In the model the rail base metal weld metal and heat affected zone have different properties of materials .

模型中考 虑了钢轨母材和 焊接 接头 材料及热影响 区域具有不同的材料属性。

The properties in weld deposit metal and Heat Affected Zone are strictly homogeneous with the base metal .

在 焊接性能和热影响 区 金属矿床严格均匀与金属基材。

However with the rapid development of modern industry the weld zones in metal components are more and more so the corrosion of weld zone has become a hot issue .

但是，随着现代工业的迅速发展， 金属构件的结构越来越复杂， 焊缝区域越来越多，因此焊缝 区域的腐蚀问题便成了当今研究的热点问题。

By using carbon extraction replica technology and welding thermal simulation the second phase particles in parent metal weld metal and simulated coarse grain heat affected zone ( CGHAZ ) of Ti-V-Nb microalloyed steel were investigated .

利用萃取复型技术，对Ti-V-Nb微合金钢母材、 焊缝及模拟粗晶 区中第二相粒子进行了研究。