奥氏体不锈钢板片冷拉变形诱发形变马氏体体积分数分析

板式热交换器传热元件为油压机冷冲压而成的不锈钢波纹板片,奥氏体不锈钢板片冷加工易产生形变马氏体组织导致耐腐蚀性能下降。为便于比较几种不锈钢板片产生形变马氏体体积分数的倾向,对304、304L、321、316L、254SMo几种奥氏体不锈钢板片进行了拉伸试验,测定了不同伸长率下材料的形变马氏体体积分数,随之对拉伸后变形率为20%试样取样制备金相试样观察金相组织并比较分析。

309L奥氏体不锈钢板热轧边裂缺陷成因分析和工艺改进

通过金相组织观察和热力学计算相结合的方式对309L奥氏体不锈钢板热轧边裂缺陷进行了分析。试验结果表明,309L钢(0.012%C,0.034%N)板坯热轧加热温度1260℃边部三角区存在大量网状铁素体,在后续加热过程中高温铁素体含量进一步升高,达到24%左右,导致塑性降低,轧制过程中产生边裂缺陷。通过控制钢中C含量0.015%~0.025%,N含量0.04%~0.05%,热轧板加热温度1150℃,使钢中铁素体含量降至10.7%,有效避免309L钢板边裂,板卷合格率达100%。

不锈钢板抗拉强度测量结果的不确定度评定

根据GB/T 228-2002《金属材料室温拉伸试验方法》标准的要求,对热轧奥氏体不锈钢SUS304钢板的抗拉强度进行了测试,分析了试验过程中测试方法、设备、量具、检验人员和测试环境等不同因数对测试环境的影响程度,并对奥氏体不锈钢SUS304钢板抗拉强度测量结果的不确定度进行了评定。

奥氏体不锈钢复合钢板(S30408+Q345R)焊接工艺及质量控制

奥氏体不锈钢复合钢板(S30408+Q345R)是近年来被普遍应用的一种复合材料,其既具有不锈钢美观、耐蚀性能的特性,又具有碳钢高强度和低成本的优点。文中结合材料性能、焊接性能、焊接缺陷等方面论述了奥氏体不锈钢复合钢板的焊接及焊接过程中的工艺要求和质量控制因素,更好地实现了复合材料的焊接。

断后伸长率A测量结果的不确定度评定

文章按照GB/T 228-2002《金属材料室温拉伸试验方法》标准的要求,对冷轧奥氏体不锈钢板的断后伸长率进行了测试,并对检测结果的不确定度进行了评定。当k=2时,置信概率p=95%,断后伸长率不确定度评定结果为A=62.5%±2.0%。

新型复合材料

新型的奧氏体钢板和聚合物芯的夹芯板结构,是一种新型复合材料。奥氏体金属聚合材料制作的轻结构可以满足高性能现代化材料的要求。

Activated flux tungsten inert gas welding of 8 mm-thick AISI 304 austenitic stainless steel

AISI 304 stainless steel plates were welded with activated flux tungsten inert gas(A-TIG) method by utilizing self-developed activated flux. It is indicated from the experimental results that for 8 mm-thick AISI 304 stainless steel plate, weld joint of full penetration and one-side welding with good weld appearance can be obtained in a single pass without groove preparation by utilizing A-TIG welding. Moreover, activated flux powders do not cause significant effect on the microstructure of TIG weld and the mechanical properties of A-TIG weld joints are also superior to those of C-TIG(conventional TIG) welding.

Softening interstage annealing of austenitic stainless steel sheets for stamping processes

To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and tensile testing were carried out to study changes and mechanisms of the stainless steel structures and properties during work-hardening and annealing-softening. The results indicate that annealing at low temperatures （100-500 ~C） can only remove partial residual stresses in the sample and the softening via annealing is not obvious. Bright annealing and rapid cooling in a protective atmosphere can completely soften the cold-worked material. In addition, the low-temperature sample without a protective atmosphere only has a little oxidation on the surface, but at higher temperature the oxidized layer is very thick. Thus, high-temperature annealing should include bright annealing.

冷轧不锈钢板规定非比例延伸强度R_(p0.2)测量结果的不确定度的评定

按照GB/T 228-2002《金属材料室温拉伸试验方法》标准的要求,对冷轧奥氏体钢板规定非比例延伸强度Rp0.2测量结果的不确定进行了评定。确定了当k=2时非比例延伸强度的不确定度。

S22053+Q345R复合钢板冷热加工成形工艺试验研究

与奥氏体不锈钢复合钢板比,奥氏体—铁素体不锈钢复合钢板在压力容器中应用的较少,相应的受压元件的冷热加工成形等制造经验较少。采用奥氏体—铁素体不锈钢复合钢板制造的压力容器,受压元件的冷热加工成形难度较大,是压力容器制造行业的共识。通过对S22053+Q345R爆炸焊接复合钢板进行交货状态试验、冷加工成形试验、冷加工成形恢复性能热处理试验及热加工成形恢复材料供货状态的热处理试验,验证奥氏体—铁素体不锈钢复合钢板冷热加工成形工艺对复合钢板性能的影响,为压力容器受压元件制定冷热加工成形工艺提供技术支撑。