摘要高氮钢是一种资源节约型不锈钢,拥有强度高、断裂韧性好、耐腐蚀性和耐磨性好等诸多优点。由于高氮的性质，高氮钢焊接过程中可能会出现氮的损失、氮化物和热裂纹等问题，从而造成接头性能的下降。因此，高氮钢焊接技术的研究具有十分重要的理论意义和实用价值。68277

本文主要研究了PMIG焊接过程中保护气体的氮分压与高氮钢焊接接头氮含量之间的关系。实验采用混气罐、减压阀控制保护气氛中氮气组分的分压:将氮气瓶和氩气瓶通过注塑管连接到混气罐下端的进气口中,焊机与出气口相连接,焊接时可以通过气压阀控制氮气和氩气的流量,并在混气罐中均匀混合,最后输入焊接中进行气体保护。焊接时保持焊接参数不变，通过改变氮分压，得到4条不同的焊缝，并获得了氮含量与氮分压的关系曲线。结果表明：采用PMIG焊接方法进行高氮钢焊接工艺试验，接头氮含量随着保护气体中氮分压的增加而增大，当保护气组分中氮气分压为0时，焊缝中氮含量为0.16%；当氮气分压达到13.60%时，焊缝中氮含量为0.42%，但氮含量增长速度逐渐减小；当氮气分压达到27.30%时，焊缝氮含量为0.46%；氮气分压为40.9%时，焊缝氮含量为0.48%，焊缝氮含量渐趋稳定，但总体小于母材的氮含量。

毕业论文关键词  高氮钢   氮分压   氮含量    PMIG焊接

毕业设计说明书（论文）外文摘要

HNS is a resource-saving stainless steel, with high strength, fracture toughness, corrosion resistance and abrasion resistance, and many other advantages. Because the nature of nitrogen, nitrogen steel welding process may occur loss of nitrogen, nitrides and thermal cracking problems, performance degradation resulting joint. Therefore, the high nitrogen steel welding technology research has important theoretical significance and practical value.

This paper studies the PMIG shielding gas welding process with the nitrogen partial pressure of nitrogen steel welded joint between the nitrogen content. Experiments using mixed gas cylinders, valve control components in the protective atmosphere of nitrogen partial pressure: the nitrogen and argon gas cylinder bottles by injection pipe connected to the bottom of the mixing tank inlet mouth, welder and outlet connected to the welding by pneumatic valve control when nitrogen and argon flow and uniformly mixed in a mixing tank, the last input for gas shielded welding. Welding welding parameters remain unchanged, by changing the nitrogen partial pressure, to obtain four different welds, and get a nitrogen content and nitrogen partial pressure curve. The results show that: PMIG welding process test for nitrogen steel welding, the joint nitrogen content in the shielding gas with a nitrogen partial pressure increases, when the protective components of the nitrogen gas partial pressure of 0, the nitrogen content in the weld 0.16%; when the nitrogen partial pressure of 13.60%, the weld nitrogen content of 0.42%, but the growth rate decreases the nitrogen content; when the nitrogen partial pressure of 27.30%, the weld nitrogen content of 0.46%; nitrogen stars pressure was 40.9%, the nitrogen content of 0.48% , weld nitrogen stabilized, but the overall nitrogen content is less than the base material.

Keywords    Nitrogen steel       Partial pressure of nitrogen Nitrogen content      PMIG welding

目录

1绪论 1

1.1课题背景及意义 1

1.2高氮钢焊接研究现状 3

1.3脉冲熔化极气体保护焊 8

2 试验材料及方法 9

2.1 试验材料与设备