In order to understand the high-temperature deformation behaviour of alloy having hard surface layer, thermo-mechanically treated duplex stainless steel (DSS) is boronised for 0.75–6 h at 1223 K and subsequently deformed under compression mode at the same temperature under strain rate condition of 1 × 10⁻³, 2 × 10⁻⁴ and 6 × 10⁻⁵ s⁻¹ until strain of 0.4. The substrate microstructure is almost isotropic with grain size after boronising with layer thickness between 1.61 and 2.74 μm. X-ray diffraction results confirm the formation of boride on DSS surface. The surface hardness of DSS increases from 387 to 1000–2400 HV after boronising. Uniform boronised layer with thickness of 20–40 μm is formed at DSS surface. Compression results show that the flow stress of the deformation increases with the strain rate and boronising time. For the boronised samples, the flow stress range is between 5 and 89 MPa. To determine the actual effect of the boronised layer on the flow stress, the results are also compared with those from un-boronised samples having similar microstructure. The results suggest that at a constant grain size, even with the hardest layer, the effect of hard surface layer on the flow stress almost could be negligible when the deformation rate is slow, but at faster deformation rate, even in the layer with the least hardness, the flow stress shows a significant increase. It is also observed that the hard boride surface disintegration could be avoided at a sufficiently low deformation flow stress that could be attributed to superplasticity.

为了了解具有坚硬表层的合金的高温变形行为，对经过热机械处理的双相不锈钢（DSS）在1223 K时进行了硼化0.75–6 h，然后在相同的温度和应变速率下以压缩模式变形。 1×10 ^-3，2 ×10 ^-4和6×10 ^-5  s ^-1的条件直到0.4的应变。镀硼后，基材的微观结构几乎与各向同性，晶粒厚度在1.61和2.74μm之间。X射线衍射结果证实在DSS表面上形成硼化物。渗硼后，DSS的表面硬度从387增加到1000–2400 HV。DSS表面形成厚度为20–40μm的均匀硼化层。压缩结果表明，变形的流应力随应变率和渗硼时间的增加而增大。对于含硼样品，流动应力范围在5到89 MPa之间。为了确定渗硼层对流动应力的实际影响，还将结果与具有类似微观结构的未渗硼化样品的结果进行了比较。结果表明，即使是最硬的层，在恒定的晶粒尺寸下，当变形速率较低时，硬质表面层对流动应力的影响几乎可以忽略不计，但是在较高的变形速率下，即使在硬度最低的层中，流动应力也显着增加。还观察到，在可归因于超塑性的足够低的变形流应力下，可以避免硬质硼化物表面的崩解。