GH3535合金的表面改性

Surface Modification for GH3535 Alloy

GH3535镍基合金的硬度仅为200HV左右,不能达到超高温熔盐液下轴承要求的400HV以上的硬度。为此,对GH3535合金进行了不同的表面改性处理,包括渗硼、喷丸预变形后渗硼和氮-硼复合渗。试验结果表明:960℃和980℃渗硼的GH3535合金的表面硬度约700HV0.1,渗层深度为0.10~0.12mm;预变形后渗硼的GH3535合金的表面硬度稍低于单一渗硼的合金,约为650HV0.1,但渗层深度比单一渗硼的合金增加了约0.02mm;氮-硼复合渗GH3535合金的表面硬度与单一渗硼的合金相当,约为700HV0.1,渗层深度达0.16mm。

Hardness of GH3535 nickel-base alloy is as lttle as about 200 HV,less than hardness(above 400 HV)which is necessary for a bearing exposed to ultra-high temperature molten salt.For this fact,GH3535 alloy wassurface modified by procedures which involve boronizing,pre-deformation with shot blasting then boronizing,and composite impregnation with nitrogen and boron.The results were as follows:(a)the GH3535 alloy boronized at 960 or 980 C exhibited surface hardness of about 700 HV0.1 and case depth of 0.10 to o.12 mm;(b)the GH3535 alloy pre-deforned then boronized prov ided slightly less surface hardness,being about 650 HV0.1,but.0.02 mm deeper case depth as compared with the GH3535 alloy boronized alone;(c)the GH3535 alloy impregnated compositely with nitrogen and boron had surface hardness equivalent to that of the GH3535 alloy boronized alone,being about 700 HV0.1,and case depth as deep as 0.16 mm.